Changed Cats but still getting PO430

I have a 2002 C4S and have been getting PO430 DTC for about eight months. Each time it happens it occurs one day after filling with gas. Always the same code: PO430. I changed all the O2 sensors, but still got same code. Cleaned MAF sensor, changed air filter but still got code. I then put in some Cat 1 Catalytic converter cleaner and then got PO420 and PO430. Brought the car to Porsche dealer and they diagnosed that both cats were bad. They cleared codes and a few days later CEL came back on, but this time it only had PO430. Same as before. I then removed Bank 2 cat and cleaned it but PO430 still came back on. So I bought two new Fabspeed 200 cell Sport cats and put them in. But still getting PO430 DTC. WTF is going on? I bought a EVAP valve and will change that this weekend. I am slowly but surely rebuilding this car. Does anyone know what is the problem? How do I solve this problem? Any help would be greatly appreciated. HELP!!!

I'm new to Pcars, but familiar with BMW's. You'd be wise to check the correct function of the ECT (coolant temperature sensor) If it is sending a lean (engine/coolant cold) signal to the ECU, the ECU will dump fuel in to enrichen...and the cats will go crazy trying to handle it....and the o2 sensors will go even crazier. (at least that's how it works in the "other" German cars) BTW- excessively rich mixtures will kill the cats...so if the stealer was right, there's a clue that you're rich. You should be able to confirm proper O2 sensor operations with a voltmeter too. When working correctly, they generally "dither' between .1 and .9 vdc...swinging back and forth like a metronome. Or, I guess most guys use a code-reader these days...showing my age a little here.

Do you have Durametric or any generic code reader that can display real-time O2 reading? Do you use Android phones?

It is possible that you have a small leak somewhere in the system causing that CEL. Sometimes replacing the gas cap is all it takes to fix, others require a smoke based leak test to correct.

This is great feedback and I appreciate it. The O2 sensors are about three months old so I doubt they are bad. Besides I would imagine that the Porsche dealership would have checked the O2 sensors as part of their diagnosis. They did a cold test to determine that the cats were bad. Strange thing is that I keep getting the PO430 code. The other side is fine. I changed the gas cap also and I still am getting the code. I also went back under the car to tighten up the exhaust bolts and to confirm that everything was seated correctly. I do not have a smoke machine unfortunately so I can't do a smoke test. The ECT (coolant temperature sensor) is something that I did not think about, however that was also replaced about six months ago when I had a transmission leak repaired after the mechanic broke the ECT. Makes me wonder if the one he put on is working properly. How do I check that? As far as a small leak somewhere, gee I wish I could find that. I figured I would replace the EVAP valve as I figured that the PO430 code keeps coming up a day after filling with gas. But then I have doubts about that too because it takes almost a tankful of gas before the ECU enters the read ready state. I have a Durametric and will try to post something soon. Maybe it will provide some clues that I cannot see. But it surprises me that Porsche did not identify anything except for bad cats. I plan on calling them and seeing if they are going to charge me again for having them look over the car again. I will keep everyone apprized. If anyone can think of anything else, PLEASE do provide your thoughts. Many thanks.

The sensors themselves shouldn't be expensive. I would check the connector on the ECT to make sure it's clean and tight. If the ECT output is missing ( bad sensor or bad connection) the ECU will default to a generic fuel mapping setting...which should be good enough to not kill cats or throw a code. However, a false lean signal (or actual vacuum leak) will result in the ECU commanding a very rich mixture, and if the limits are reached, codes get thrown and cats can grenade. The Bentley should cover checking the ECT, but I'm not at home to check it.

Sitting in a lobby having my 996 aligned and had another point. If you can monitor the o2 sensor voltage outputs, they will tell you what the ECU is doing- If the voltage is fairly steady towards 1vdc and not "dithering back and forth low/high/low/high....then the ECU is commanding a rich mixture. It should only do that for real or perceived lean condition or a real or perceived "cold start" That means if everything else is working, you have a post-MAF (unmeasured) vacuum leak or a bad ECT signal. You can track down vacuum leaks with some carb cleaner if a smoke machine isn't in the cards.

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Since you have Durametric, you can check the coolant sensor readnig at start up and when moving to see if they give reasnoable values. You can log the O2 sensor voltages on all 4 sensors on both banks. After engine has warmed up, at idle, precat sensors should swing between 0.2-0.8v about once a second. Post cat sensors should read about 0.7v almost steady most of the time. If you see the post cat reading kind of following the precat readings, your cats are shot. Now repeat the above but drive the car around. The pre cat should swing a few times a second when the post cat will still be around 0.7v most of the time. If you accelerate, both pre and post cat reading will hit ~0.9v almost instantly When you let off the gas quikly, both reading will go to 0v almost instantly. Also, compare the post-cat readings on both cats. If it's not stable at 0.7v in bank 2 (P0430) most of the time, your bank2 cat is marginal. Should be obvious once you overlay the readings from both banks.

I don't know what this Durametric is, but I haz to have one. Lol

I had a similar problem when I replaced my cats with the Speed Venture X pipe and high flow cats. After the installation, the codes were clear; however, about a week later, I had P0430 & P0420 codes pop up . I went back to my mechanic, and he checked and could not find anything wrong and we decided to replace the 02 sensors. Since then, no problems and it has been about 1200 miles since the installation of the Speed Venture equipment . In other words, you may need to run your car a few miles until everything settles. Good luck

FWIW- and I don't mean to suggest I know whats wrong with your car, by any means... The testing of the ECT is found in Bentley 24-11. Overview: remove the plug from the sensor- with key "ON" should see the standard 5vdc reference voltage (Motronic uses a "bus voltage" of 5v) If no 5vdc in the plug, check wires back to the ECU for continuity. Sensor resistance tests: (with ohmmeter) 32F = 5-7k 68F= 2-3k 180F= .4-.8k The ECT is a thermistor, which is to say a variable resistor based on temperature...the above values show the acceptable resistance for the sensor. (Replacement sensors should be about $20) **after reviewing the original post- you might confirm that your fuel tank vent lines are clear and open (able to vent) I missed the "full tank" correlation. BTW- Checking a cat is easy with a cheap digital thermometer from Home Depot: Once warmed up: Outlet temperature should be almost double the inlet temperature. (as measured on the inlet and outlet of a cat) Werd

Well, here is a quick update. Since it is cold as hell here in New Jersey and we have ice on the ground I decided to contact the Porsche Dealership who told me the original cats were bad. They agreed to look at the car for no charge. Um, that sounded like a fair deal. So I brought the car there. They checked the car and said that the Bank 2 cat (passenger side) is bad. They also said that since these are aftermarket cats, they cannot say with any certainty that I will not have a problem with the other side. What a PITA! So I called Fabspeed and they told me that I need to put an O2 extender on and that will fix the problem. Um, that sounds like a bandaid. I am thinking, now what? I asked if they checked out the health of the o2sensors, they said yes, and that everything else in the car is working fine. I am thinking I may change the o2 sensors as Larry did. Or maybe I will just drive it for a few thousand miles since the o2 sensors that are in there are about three or four months old and maybe 3,000 to 4,000 miles old. Any thoughts?

Spend $10 and get the extenders. If they solve your problem, consider yourself lucky that a $10 fix would let you move on with life(especially on a Porsche).

OK, this may be a stupid question, but I think my cats are bad and don't want to get in the same situation as the OP - replacing them and then still getting a CEL fault. The question - other than a rattling noise, is there a definitive test to tell if a catalytic converter is bad?

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Yes, check out post #8 above. Oh, if you use an Android phone, I can tell you an even better and accuate way. Let me know.

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Well, yes there is. For a P0420/P0430 if the errors are accompanied by aging O2 sensor errors replace the sensors indicated, clear the codes, the resume driving the car. If theP0420/P0430 error comes back, or are present without any aging O2 sensor codes, replace the converters indicated. Now, with my Boxster I have managed to nurse a sick converter (the error code is P0430) for a number of years by running a top tier gasoline -- switched to discount station gasoline some years ago when gas prices skyrocketed -- Shell being the most common since there is a station near me that has competitive prices and is convenient to use.

Hey TsMcNeill. Durametric is a great diagnostic tool, as long as you know what all the data means. It is pricey thought, about $300.

Hey kcattorney, To see if you have bad cats your options are: to either go to Porsche and for an hour labor they will do a diagnostic test, or go to Harbor Freight and buy a Centech OBD2 reader for about $100 and check the codes yourself. I have the Centech OBD2 reader and the Durametric software which cost $300. Both work well. My issue is that I do not understand all the technical data. But in my case, I heard the rattle for a while, and was hoping for the best, I checked it with both readers and got the PO430 code, and erased the code for months only to have the code return every week. I then tried everything I could think of and researched like crazy. I even took the cat out and cleaned it, that work for an extra day, but that is it. So my options were to buy new OEM cats, which our local Porsche quoted me $6,000 plus $700 for labor, or buy OEM cats from Suncaoste Porsche in California or Sonnenporsche in Califormia for $1,700 each or have my existing ones remanufactured by Smithcat in Illinois for $450 each or go with aftermarket with Fabspeed. I chose Fabspeed and you can see my problem. Not sure what the right decision is or would have been, but as you can see I am still working on resolving a very frustrating problem. Good luck.

Larry, Did you get po430 or 420 when you replaced your cats with the sport cats? Thanks, Fernando

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Fernando, yes, a couple of weeks after installing the Speed Venture cats, both codes came back on and that is when he changed the 02 sensors. Since then, no error codes and it has been about 1500 miles

Thanks Larry, I am leaning toward new O2s. Update: Well, my wife just picked up the car from Porsche dealership. What a waste of time, but fortunately they did not charge me anything. All they did was hook up the pst2 to see that the cat is bad. They did not check anything else to see if anything caused it to go bad, if the o2 sensors were bad or anything. All they said was that these are aftermarket cats and they are far inferior to the OEM cats and that I should expect more CEL in the future. So I will hook up my Durametric to the car tomorrow and post on here and hopefully someone can see something in it that I can fix and resolve this problem. Thanks for great information and assistance. Fernando

You guys over analyze and make things way too hard...

The only way to diagnose the problem is to look at the wave form for the rear O2 sensors and compare them to the front o2 sensors. You can do this with the Duramemetic scanner, you cannot do it with a cheap code reader. A proper wave form for the rear O2 sensors will have very shallow peaks and valleys because their should be very little oxygen coming out of the cats ,Think of small waves. The front os sensors will have high peaks and valleys as the PCM controls the fuel trims. If the rear patterns are following the fronts in unison, the cats are not doing there job. Short of an exhaust leak and assuming the O2 sensors are functioning correctly, I would condemn the cats. It takes some experience to diagnose a failing O2 sensor, when they get weak they will not generate enough voltage or flat line and the voltage will not change at all. When this happens it will normally set a code for the O2 sensor but not always. The cats and O2 sensors have to be hot. The O2 sensors have heaters built into them to get them up to temp faster. Sometimes the heaters will fail but again this will most likely set a code for the heater circuit. I see aftermarket cats throwing cat efficiency codes all the time. There is a reason why the OEM cats are so expensive. Yes you can fool the PCM using O2 extenders, but after spending big money for the aftermarket cats I would hold the manufacturer feet the the fire to correct the problem or refund your money. Here is a generic image of the O2 wave forms, The top is what the rear should look like, the bottom is the front. If the rear o2 sensor looks like the front, the cats are bad. Your time at the dealer was not wasted, It does not take a lot of time to look at the data, and they see aftermarket cats causing this type of problum all the time.

Hey DGmark, Can aftermarket cats be fixed or made to work? I am in discussions with Fabspeed and they will test, fix or replace the cats? Even though the salesman insisted that all I needed to do was add extensions, their Porsche tech agreed to help me out and fix the problem. We got to this point after they spoke to the Porsche dealership. However, I did not feel comfortable hearing the Porsche dealership mechanic tell me that these aftermarket cats are weak and will throw inefficiency codes again in a short time.

Your tip off that they will not correct your problum is the fact that they want you to use the extenders. What that does is pull the O2 sensor out of the direct exaust stream and slows down the O2 crossover on the rear O2 sensor. A proper "Quality" cat will not need the extenders and If you are in California the extenders will most likly fail the visual inspection. The funny thing is that it is random with aftermarket cats, some have no problums

Thanks DG for the response. Well, I am glad I have the Durametric, it is fun to use, but I can't tell if anything is wrong with anything. Here are a bunch of values, so if someone can make sense of this, please let me know. Pre and post cat o2 sensors results were nearly identical. Bank 1 Rear O2 voltage .09 to .8 resistance reading 64 Front O2 voltage .10 - .75 resistance reading 64 Oxygen sensing fluctuated very slowly between .99 to 1.02, but mostly stayed steady at 1.00. Bank 2 Rear O2 voltage .10 to .8 resistance reading 64 Front O2 voltage .09 - .77 resistance reading 64 Oxygen sensing fluctuated between .99 to 1.02 Engine temperature 90.8 Celsius (195.44 degrees F) Exhaust after cats 320 degrees Celsius (608 degrees F) Carbon Canister load fluctuated from .06 to .27 Cat mean amplitude 180 for each bank Hot Film MAF 1.25 oil temperature 86.3 Celsius (187.34 degrees F) Ready Status: Everything except for catalytic converter efficiency passed. Can anyone see anything in these values that would explain the PO430? The CEL was cleared at dealership.

Fernando, This is the unit that I installed in my car. Not only did it clear the codes, but in really increased the performance and sound of my car It is important to remember that it will pass emissions , but it will not pass visual inspection in California . It just depends on where you take your car for smog testing. Good luck.

Ok, It looks to me like the cats are not reaching threshold temps. The cats lite off at 650-700 degrees and normally run between 800-1100. look at 2 more things, check the long and short term fuel trims, they should be between -5 and +5, they will fluctuate higher and lower thats OK we are looking for an average. Next run the engine at 2500 rpm and let me know what the converter temps are, we need them to be above 700. If you have an infrared temperature gun that goes over 800 degrees you can check the inlet and outlet temps at the converters. You are looking for a 100-200 degree increase at the outlet temp, that means the converter has lit up and is working. If on extended idle the converter temp is dropping below threshold temp that is what is setting the code. I want to tread slowly before condemning the cats because your original problem was only a p0430 and this code has continued even after changing the 02 and cat lets see if we can nail down a definite diagnosis before jumping on anything. "but I still think its the cat." Class, Class, "Wake up"

dgmark's knowledge far exceeds mine on this, but I do know that there should be a marked jump in measured temps between inlet/outlet of the cats at operating temperatures. Also, in a 4-o2 system, the pre-cat o2's should be busily dithering between .01 and .09 vdc.....and post cat o2's should be fairly voltage stable at .5 or so vdc if they are monitoring a fairly stoich exhaust. I know how to measure those things manually, but am unfamiliar with code readers....so I would heed dgmarks' advice...it looks sound.

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I agree but reality is 200 cell cats have been known to cause cel lights in all cars, and not just specific to Porsche. Having more flow and less filtering, you are always rolling the dice. As you said, the problem isn't consistent and can be random between cars. One explanation is that manufacturers often update their ecu's slightly throughout their production run to improve or account for any previous issues or make minor improvements. So some might have slightly different parameters, including a lowered cat threshold value. With OEM readers you can see the ECU revision version(can't remember off the top if Durametric displays this). That's the reason why some guys can run a full cat bypass with O2 extenders and not set off a cel, while others with a more finicky ecu version will trigger cel even with performance cats. If we actually had a decent sample set with peeps running performance cats and with ecu revision #s recorded, you might see a correlation with certain versions. But as indicated OP indicated, you can check the temps to make sure you didn't get faulty cats. Oh btw, if you ran too much JG-DT40 oil, you have only yourself to blame for cat malfunction/ failure.

If this is not a typo/transcription error on your part: Bank 2 Rear O2 voltage .10 to .8 resistance reading 64 Front O2 voltage .09 - .77 resistance reading 64 Oxygen sensing fluctuated between .99 to 1.02 The rear O2 sensor voltage is wrong. When the voltage drops that is from oxygen in the exhaust gas. The converter should "latch" on to that oxygen, store it, and use it for processing exhaust gases. (When the CEL comes on in my Boxster and I have the scan tool hooked up and look at the #2 O2 sensor voltages I see some thing similar. The #2 sensor voltage level is fluctuating and I know it should not do this, but remain high (> 0.6 volts).) As I mentioned in a previous post -- which was from the factory manual -- that if the converter error codes are not accompanied by aging O2 sensor codes -- the converter indicated by the converter error code is bad and should be replaced.

Macster, Quest & dgmark - Thanks very much for the info. This thread turned into a great tutorial on how cats work and diagnosis of problems.

I had all these issues - had the 'cats are bad' you should change them, etc, etc, etc. Found out you can't clean a MAF if the MAF is BAD.... Change the MAF first - then drive the car for a hundred miles and then reset the codes (if they come back after the MAF change). It is surprising how many codes can be generated by a MAF giving bad info to the ECU. Coolant sensors and air leaks are rare unless like me you had the after market air intake off and didn't get it back on correctly. Oops... And don't buy those ebay cheapo MAF's like I did - lasted one year and then crapped out - buy the OEM part.

There are always exceptions to the rule but in this case the evidence points to the converters. MAF problems have their own error codes. If the OP wants to try this he can disconnect the MAF from the wiring harness and clear the error codes -- to reset the adaptation values -- then drive the car normally for a while (roughly 30 miles) to see if the converter error code comes back. There is the risk the code won't come back because of the way the car is being driven or because of fueling issues absent the MAF input. I have driven my my Boxster 275K miles and the last time I cleaned the MAF was back in Feb. 2004 when what proved to be an AOS failure was causing the engine to act up. Oh, the engine had 80K miles on it at that time. The 2nd time the AOS failed I never bothered with the MAF I just had the AOS replaced. The Turbo has 115K miles on it and I do not know where the MAF is. Back to the error code... there can be other possible causes, at least for other models. For instance my Turbo P0430 section starts out with making sure the front and rear O2 sensors are not swapped. This is because the two sensors are different. The front one (the #1 sensor) is a wide band sensor while the rear (the #2 sensor) is a narrow band sensor. However, the 996 NA doesn't use wide band sensors. There is also a check made for proper valve lift operation. The OP can certainly have this check out performed. IIRC itt takes two techs one to drive the car one to hold the data logger to capture sensor data under test conditions. There may be other tests/checks. I have a copy of the factory manual but I may not have all the updates/TSBs/whatevers. Only a trained tech with access to all the factory repair information can know what if any other tests/checks there to eliminate the converter and identify what other component or system is responsible for the error code.

Hey DGMark, I hooked up my Durametric again, but I could not find the fuel trim you mentioned, so I could not get that information. I went into the Engine ECU? Where would I find that? I did rev the engine up to 2,500 rpms, got the cats up above 700 degrees F, checked the o2 sensors and after some funny things with the sensors, like the Bank 2 rear sensor looked like it was following the front sensor for a few seconds, it then followed the same consistent straight line pattern as the Bank 1 rear sensor. Before I started going through the values analysis, I checked on the car's Readiness Status and it said the Converter failed Readiness, but after going through the values analysis, reving the engine, I went back to the readiness status and it said all parameters passed Readiness, INCLUDING the cats. I then went to see if any codes came up and found none. Does this mean this problem fixed itself? This is too strange. I am getting gas today, so I will know tomorrow, which is what usually happens, CEL after filling.

This is something for kcattorney, I was having CEL po43 come up on my car for about 8 to 10 months before I changed the cats. After I went to the Porsche dealership to have it checked out they told me the passenger cat was bad, I looked at my options and tried to clean it first. I took the cat out of the car, removed the o2 sensors and put the cat in a large heavy plastic rubber maid container measuring about 3.5 feet long, 2 feet wide by 10 inches deep, filled the container with 16 gallons of hot water, straight from my hot water heater. I added a quarter cup of detergent, a third cup of dishwashing liquid, and a third cup of citric acid (orange oil). The cat was fully submerged in the water. I then put a clear plastic tube on my air compressor and inserted the tube in the long pipe end of the cat (so it would force water in the opposite direction of exhaust flow) and set the air pressure at 5 psi. When I first started this, some bubbling air came out of both sends of the cat assembly. I think this means the cat was partially clogged. After about 2 hours all the bubbling came out of the opposite end of the cat assembly, so I think it cleared the clog. I covered the container with the cover and some heavy flannel shirts to keep it hot. I ran the compressor for about 5 hours. I then let it soak over night and drained the water and refilled it again, but this time with clear water and ran it for about three hours with the compressor set at 5 psi running and pushing air completely through the cat assembly. After this I rinsed the cat with a few gallons of hot water to make sure I got all the saop out. I then let it dry for a day indoors and put it back in the car. The CEL came on about one day later than it just too. But I was still getting a rattle. The long and short of this is that I think I cleaned the cat, but since the cat was already shot, it would not function properly anymore. The rattle was an indication. My lesson from this is if I ever find out that I have a clogged cat, I will take it out and clean it as mentioned before the inners gets damaged by the back pressure. Good luck kacattorney.

The converter is not fouled with anything that can be removed with detergent and water. The potassium component of ZDDP can coat the working surfaces of the converter and reduce its efficiency. Another failure mode is the converter proper (brick) can come loose and shift out of position and this can affect air flow through the brick and reduce its efficiency. This can be caused by driving the car with the CEL flashing. This flashing is a sign the converters can be at risk of overheating due to rich misfires and the excess unburned fuel that results when burned in the converters overheats them and can ruin them. In this case the brick can come loose or just partially melt/collapse. The converter can wear out. The converter sheds its catalyst metal over time (atoms at a time) and if the converter was on the low end of the coating quality scale this can have the converter simply lose enough of its catalyst metal to reduce its efficiency to the point the error code is generated. Less common, much less common, is running gasoline with lead in it.

The intermittent aspect of the error is what I would expect, and have experienced over years with my car. If I watch how I drive -- avoid the more sedate steady state speed cruising -- and keep the RPMs a bit elevated -- mainly by using a lower gear than I would otherwise -- keeping RPMs above 2500 I can keep the CEL away a long time. But this doesn't alway work. Colder weather seems to bring the CEL more often than warmer weather even though I use the car the same way season to season. Also, as I mentioned before, discount gasoline seems to affect how readily the CEL appears. Switching from a discount premium gasoline to Shell V-Power cut down on how often the CEL appears considerably. The gasoline doesn't have to be Shell. Chevron works as does Unocal 76 or Philips and there are other name brands but they must be top tier gasolines.

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The fuel trims are listed as FRA (long term) and RKAT (short term) under DME. The O2 reading you described means a marginal bank 2 cat. As long as the post-cat sensor reads 0.7v steady most of the time when cruising, the cat is good. The fact that the bank 2 cat follows the pre-cat reding a little before settling down to a steady reading means the cat is marginal. If you cruise then slow down to a stop w/o applying gas, the post-cat reading should stay at 0 and creeps back up slowly to 0.7v steady at the stop. If it creeps up quickly, it also means the cat is marginal. Best is to plot reading from both banks the same time and it will be clear how they different. Your car is fine for now as the cat test has passed (will pass smog now). The cat test is performed only from time to time so you may be OK for a while until the next test. Then due to its marginal nature, you may or may not trip the CEL.

BTW, when I said the cat is bad, I meant it's not as efficient as the stock cat, which the DME is programmed to expect. If I remember right, the stock cat is 400 cell so twice as efficient as your 200 cell. So it's difficult to conclude whether your bank2 cat is performed as designed or it's really below its own spec.

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Ashai hit it on the head, Its not that 200 cell cats are quote bad, they are not as efficient as the stock cats and will trip the cat efficiency codes. My bias is toward the stock cats for this reason in a street car. Every time you clear codes the readiness monitors reset and you have to go through a drive cycle to run them. It looks like you don't have any other issues If you can look at the fuel trims and they are good. The manufactures should be clearer regarding cat efficiency codes and their converters. I have been told by some manufactures that they have never seen this problem and I must be doing something wrong. This just pisses me off.

Thanks Quest!

Thanks Ahsai for the information. And thanks Macster for the information. I know the catalyst brick loosened up in my orinal converter as I used to hear it rattle at times, but when I took it off the brick looked intact. Since putting on the new sport cats, I have not heard any rattles. On another note, I have to give some "customer credit" to Fabspeed because they agreed to replace the cat that is giving me trouble. They have a mechanical engineer who works there who is very knowledgeable and very customer focused. So rather than try to experiment and hope that I do not get any more CELs, I am going to Fabspeed and have the cats changed. Getting CELs in less than two weeks with new cats is definitely a problem. Thanks to all.

Final update: I figured I gave enough time to complain about my Fabspeed cats, and I must give at least a final update to comment on my visit to Fabspeed and the resolution of my problem. Fabspeed agreed to test and repair or replace my cat if I went to their facility at no cost to me. So I took the two hour drive in pouring rain and went to their facility in PA. What a gorgeous facility it was. But what impressed me most was the courtesy and interest in trying to resolve my problem by their people. They inspected my exhaust system, took it apart, tested it and replaced what appeared to be the problem cat. They had us sit in a large waiting area with a huge flat screen tv and fire place. They gave us a tour of their facility. What an impressive facility it was and they had some really cool Porsches and Ferraris there. The long and short of it is, my cat was replaced by Fabspeed at no additional cost and their people were fantastic. I must admit that I was very pleased with them and I no longer have a CEL. What a relief! I can honestly say that I highly recommend Fabspeed for anyone thinking about going with aftermarket cats.

Glad to hear you have it sorted out and kudos to Fabspeed.

Normally you always try to resolve it with the manufacturer before complaining here and getting everyone involved IMO. Glad everything worked out. 3 pages...