Failed CA Smog

My Porsche failed smog testing today. It was explained to me that it failed at 15mph in the category of (essentially) unburnt fuel..it registered 55, with a maximun allowable reading of 48. I expected it to fail the visual inspection, not the sniff test (see my signature for mods). The only mods that I have added since the last smog test, are the high flow cats and the LWFW. The mechanic thought it failed due to the GIAC flash (which I told him about after the test). I thought that would be a simple fix...have it flashed back to stock, or get a spare junkyard ECU. The business that did the flash no longer works with GIAC. The ECU is VIN specific. A new ECU is just shy of $5,000 from Porsche. The company that did the flash suggested that the high flow cats were more likely the cause of the problem. I guess I should not have sold my stock cats. Does anybody have a set of stock cats to sell? If not, Ebay here I come.

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Hey Mark, that's a drag. I guess the cats are the cause; mine just passed again a couple months ago, I'm about 70k miles now. Seems like you should be able to find a cheap set. Kind of a drag, but I'm sure it'll work out for you, GL.

ED, PM replied. Thanks. Dave, there is a set on ebay, cheap...if I can't find them here. I sold mine because they were a pain to store in my garage...that will teach me. Thanks. CA smog sucks.

I still have the cats from my 99 2.5L Boxster. Can they be cut and welded to work in your application for this time of year?

Hey Dell, thanks for the offer. I don't know if they can be made to work. There is a set currently on ebay for my car or Ed has a set for my car. Does anybody know what Ed should sell them for? Thanks.

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The smog and car requirements really do suck. Good luck getting out of there.

Mark, just let me know if the other sets fall through. If you can put something together with mine to get past smog, just cover my costs to ship to you and they are yours. Obviously you probably prefer the 996 sets but just know mine are here if you want them.

Dell, that is an incredibly generous offer. Thank you. I will let you know if I can't find a set for the 996.

No problem at all. Anything to help out. I can't imagine how difficult it is to drive a car in Kalifornya with all those insane rules.

Mark.... you should be able to go to any GIAC dealer. Your stock program is VIN specific and should be stored in the main GIAC server.... is the high flow cats 200 cell? I cant believe it failed.

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As of this May failing was 58 ppm (HC), not 48 at 15mph. Failing at 25mph was 42ppm. Sincerely, Macster.

Too bad Mark, just another issue to deal with. Nice to see so many generous offers, hope it's easily solved for you.

CA smog sucks! Mine didn't pass either.

You could borrow my ECU if you lived closer to see if that allowed you to pass. Swapping cats sounds like quite a bit of effort - best of luck!

I passed the 86's very last required smog test, in washington, it will never need to be inspected again (unless they change something) sorry man, not like we have enough things to worry about... now you have an expiring tabs AND the car isnt thru smog good luck on a fix - maybe you can "borrow" someone else's for an hour

Mark, I'm not sure if it's the cats. My car passed smog with similar upgrades as yours, except for the ECU tune. I had the plenum, intake, headers, 200-cell cargraphics, and a pse-hack.

Sounds like a market in renting ECU's

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I think it could still be from the cats, but more likely both the ECO flash and cats together. Do you still have all the lambda (O2) sensor locations hooked up? The cats get super hot in normal operation (as we all know), which also has the effect of burning up raw fuel vapor left in the exhaust. With some high-flow cats (and certainly with no cats) you can get more raw fuel in the exhaust at the tail pipe. When really severe it can cause backfires on downshifts. Having the the lambdas in there can help the ECU to compensate, but without them it'll def be no go. Big mods can do things, as can a whole bunch of little ones added up. Just food for thought.

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Lambda sensors were still connected. Actually, now that I think about it, the ECU might lean-out the mixture, anyway, won't it?

Thanks for all the advice guys. Sharkwerks convinced me that it is the high flow custom cats. I would have bought a junk yard ecu and swapped..it can not be done. I bought a set of stock cats off ebay for $173. I sold my old ones for $150..so not a big deal...just a PITA.

Good luck passing. What do you have to do? Put breath mints in your gas?

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Run a mixture of 50% gas and 50% water. It sucks that it's the cats for Mark's car. Changing the cats is easy but still time consuming and PITA.

Speaking of breath mints for the gas...are there any additives that will improve my chances of passing? (aside from snake oil) Since my issue was unburnt gas, perhaps a little Beano in the tank will help.

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Unlikely. A few smog checks back for my 02 Boxster (with at this time 184947 miles on it) I was concerned about its passing and arranged to run a couple of bottles of Techron through the engine, then had the oil/filter changed and new plugs installed. I can't be sure now but I might have replaced the air filter too. Then on the day -- and I picked a hot day -- I drove the car a long while -- 30+ miles and even filled up the gas tank (low fuel light on) with 6 gallons of 100 octane racing gas. Engine passed with flying colors. Numbers higher than average but still well within the limits. I spoke with the tech and he told me either a car passes with some margin or it fails by no small amount. It is rare a car's on the fence, teetering between passing and failing. About all you can do is make sure the engine's in good tune. This means fresh plugs, correct plugs, there are no marginal coil packs, air filter fresh and installed properly (I don't know what if any effect an aftermarket air filter would have cause I have not used one in my Porsches), the engine's got fresh oil of the proper type and viscosity and is not overfilled with oil. Then be sure to drive the car alot on the day of the test and arrange to keep driving it up to just before the test. Have the engine and drivetrain up to operating temperature. Avoid using the A/C cause this causes the fans to run all the time and this lowers the engine's coolant and operating temperature by a few degrees. Then cross your fingers. However, with a modified car, as you found all, all bets are off. With high flow (and probably low efficiency -- deficient in the very important catalytic metals that help oxidize emissions gases) converters installed and a chip reflash/tune that probably runs the engine at a richer than ideal mixture required by the converters to deliver their best performance well I would have been surprised if the car passed. Oh, I forgot to mention: The most recent smog check on my Boxster, done early this May -- with I don't have the smog paperwork in front of me to note the mileage but it was probably close to 225K (or more) miles (car has nearly 234K miles on it now) -- I did almost none of what I did the previous check in 2008. No racing gas, but I had made it a point to run Shell premium gas for the several weeks before the smog check, the plugs were "old", the oil probably not real old, cause I change it every 5K miles, but not recently changed either (but the oil level not real high either), the air filter not fresh but not that old. The only thing I did was to clear the P0430 error code (arising from a worn out converter) and then drive the car long enough to get the engine/drivetrain nice and hot and verify enough of the readiness monitors were set to complete then as soon as I saw the smog check shop had an empty bay I drove right in and arranged to get the car checked. It passed, but by not as much margin as it had in 2008. But it passed. Sincerely, Macster.

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Macster, thanks for taking the time to post all of that information. When I get the stock cats installed, I will go drive the car hard, with the AC off, prior to having it tested. I passed smog with flying colors a couple years ago. The cats amd LWFW are the only changes. Hopefully, the stock cats will do the trick. 234K miles on your boxter is very impressive. Has the engine been replaced or rebuilt?

Mark, This guy had posted this for over a year so you probably can get it for a good deal on it. http://sfbay.craigslist.org/eby/pts/1858301594.html I used IsoHeet in the past to pass smog on my borderline cars. It burns cleaner.

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Original engine. Original clutch. Engine still runs good and while oil consumption up a bit -- to nearly 1 quart in 5K miles -- it is not yet bad enough to be a hardship by any stretch. Best car I've ever owned. Sincerely, Macster.

I wanted to update what happened with my cars, in case someone else experiences this problem. I installed the factory cats, that I bought off ebay. I did not even install the rear bumper to go get it smogged. I heated the car up and left it running, while I was waiting for the test. It passed with flying colors. I drove it home and promptly reinstalled the high flow cats...it sounded terrible without the high flow cats. What a PITA. On the same day that I has the Porsche retested, My wife brought her 2001 Mercedes SL600 (with 55,000 miles) to have it smog tested also. It failed...at 15 mph it had 47ppm of CO2...passing was 44ppm. It is completely stock and runs perfect. I went to Kragen and bought a can of CRC "Guaranteed to Pass" additive and followed the instructions. I just came back from having it retested. I was hoping that between the additive and really warming the cats up, it would drop the 3ppm necessary to pass. It passed with the CO2 reading at 4ppm (down from 47). All of the other readings were at about 0ppm. Both the tech and I were amazed. I will never take a car to have it smogged again without adding that stuff. For less than $10, it was money well spent.

Thanks for the info. I just had mine pass smog last month as I kept my fingers crossed. I will pass on the info to fellow drivers. Thanks again.

Sorry to hear about the problems Mark. When we lived in CA I never used to take my cars for smog without driving them for a good half hour, as you said, to get the cats warmed up - it makes the world of difference. I can imagine your frustration, as California smog tests are so bogus at the best of times. Pity that you had to go to the trouble of swapping out the cats.

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Interesting info about that CRC stuff. Never heard of it. I wonder if it helped or the fact the Mercedes was driven more before the 2nd test was the factor that contributed to the car's passing smog? It is so important to drive the car a while -- 30 miles or so -- if possible with the A/C off -- to get the engine and all nice and warm. If the car sees mainly short hops a longer drive may be even better to well blow the cob webs out. I'm going to see what I can learn about that CRC stuff, what's in it. Sincerely, Macster.

The below link is for a bunch of amazon results for the CRC product. I did see one forum where people had performance problems from their cars while running the stuff. But these were cars I feel would have a problem of getting out of their own way. I'd imagine possibly the best thing would be when low on fuel then only make half a tank solution instead of being stuck with a full tank of snake oil. http://www.google.com/products?hl=en...ed=0CCIQrQQwAA

Nice ending Mark. Glad your Porsche and wife's M car both finally passed. How's your back theses days/

From Macster's posting it's clear that you just make sure that you have properly serviced the engine so that it runs optimally--that is truly the reason for the California smog tests--to make sure these cars are tuned for optimal performance--and thus they put out less smog. The final solution to all this smog stuff is when Porsche puts a diesel engine in the 911! Never again would a smog test be needed--as they never test diesel engined vehicles.

996 Fan, you are very welcome. Wayne, Thanks. I am really glad that it was the cats and not the ECU. Macster, the only difference on the Mercedes, other than the additive, was that I left it running prior to the test. I believe that the additive made most of the difference. The smog shop is far enough away that the car is completely warmed up, by the time I get there. Steve, thanks. From your growing list of mods, it sounds like you are enjoying your Porsche, as much as I am. The 99 996, with LSD and no e-gas is a keeper. My back is ok. After 7 surgeries, hopefully, I am done. Thanks for asking.

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figured the stock cats would solve the issues for ya just hold on to them as you'll need them every couple of years. FYI high flow cats will eventually trigger a cel and don't seem to last a long time but at least you'll have the stockers if/when needed one can also retune and desensitize the 02s but...

Hey Alex, thanks for pointing me in the right direction. I appreciate you guys taking the time to give me the right answer. You are partially responsible for my mod addiction. You did a few to my car under the previous ownership and your project "White Shark" convinced me to do the others. It remains one of my favorite examples of a modified 996. The sound clips were what really sold me on the LWFW.