Defective catalyst from day one

Hi Guys Just got a call my the local Porsche Garage, and they finally figured out why i on long trips get a CEL light with the classic "Catalyst warmup failure" code, two new catalyst converters needed, but this CEL has now been there from the beginning when i got the car from new, back in 2007, but as they first figured out the problem now, then its my own wallet that must pay for two new catalyst converters :-o I know that it was stupid back in 2008 to clear the CEL my self and only take the mechanic for a test drive and it didnt show, but i dont think it would have been much of a difference, because in 2009 when the CEL again came back, they shut it off as well and told me just to drive along, there was no issue, after that i have just shut it off my self, its only on very long trips it comes on. I love my Porsche, i love the brand, but i now hate the crappy service, the car has only run 47.000km, and its totally crazy that i need to change the catalyst converts allready, especially as they have been defective since 2008. The car has a full service history at Porsche. What would you guys do? By new stock ones, og get some upgrades?

Hold on. Since from the above question it sounds like you have not yet replaced the cats, how do you know that these crappy Porsche service guys aren't just guessing? You're right. It shouldn't fail. And in the US, the emission control equipment has a longer warranty (8 yrs or 80K miles). Check your local laws. Also, since you can document that you took the car in to be fixed while under warranty, and all they did is reset the error condition, you should get Porsche to replace them.

Hello Fjeppe, I'm sorry to hear about your misfortune with Porsche. Fabspeed does offer an aftermarket alternative than the dealership with the highest quality HJS Sport Cats from Germany. Please let me know how the situation plays out with the dealer, and I'll be sure to work with you in the event it does not end in your favor.

If u have to pay for the replacements id go for the aftermarket ones, and find a good indie shop. If they don't require emissions inspections where you are I'd get the straight-thrus. If u are one of the few where they must be OEM, you could hunt for some takeoffs. If the dealers shop won't fight for me, I wouldn't give them any more business than forced to. If that shop is on my side and saves me money and aggravation, then I'm more loyal to them. That's me. But u did make a mistake by ignoring the issue. Let us know what happens...

Hi all And thanks for all the replies. The problem about the warrenty is that it didnt get registered, as i did the reset myself first, and then took it to the dealer to see if it could be replicated, so they didnt do any registration, until i retuned the year after with where i didnt turn off the CEL myself, here i was 9 months overdue the warrenty, but this visit got registered. They told me today when i picked up the car from service, that back i 2009 the issue didnt appear that big so thats why they didnt react, but now they feel that we should change the catalyst, the car runes just fine. Trust me if it was something else and i could fix it, i would be the most happy guy ever and event through i little victory dance at the local Porsche Garage, a couple of year back they also false diagnosed my VW Golf 5 R32, (They also do VW) and change first the DSG ECU, then clotch, then flywheel, with no change, then i went to a specialized garage, and they fixed the issue with a software update for just 300 dollars, compared to the 7000 dollars misdiagnoed. But i dont have any other qualifyed guesses other then the one from Porsche, so im currently looking for used catalyst in germany, they are fairly cheap, the aftermarked are almost as expencive as the stock ones and a bit over my current budget, as i got a service bill at 1200 dollars.

Fjeppe, While you may save money with used or factory cats, you may also sacrifice longevity of the cats or resolving the issue you currently have

Hi i don't know if you sorted this out but the same thing happened to me and my CS 2007 where the cats failed after 54000 KM. looked around quite a while and found used ones from a reputable dis,antle firm here in sweden. Closer to you as they are in Malmö. I got the shop who i bought the car from to pay for everything which ended up close to 3500 Euro in total and I am very happy he paid for the whole thing even though I bought the car a year earlier. All The Best and let me know if you need the number to this firm as they have a few left from 3 crashed Cayman S and Cayman 2007 with only 22000 km on them.

A lot of shops will take you for a ride just because they can. I would go to a 2nd shop and get a second opinion and second quote before dropping major bucks on this. Don't mention the previous shop telling you that you need new cats, and see what they say.

What CEL code did you get? And what caused you (or the Porsche center?) to conclude a faulty converter? Usually the converters in these cars are bulletproof, if they fail they will also start to rattle. What fails is often the O2 sensors. And they will often give the same CEL. Since no one has suggested it yet, have you hooked your car up to an OBD2-logger and run some diagnostics? You seem to have the tool since you can reset the CEL. I would log the fuel mix (LAMBDA), as well as the voltage output from the o2 sensors. Do this when the engine is fully warmed up, the voltage should constantly change between 0,2-0,7 volts iirc. Could be 0,1-0,8v as well - point is that it should constantly change and always be over or under 0,45v when in closed loop (i.e car is warmed up and running of its sensors to determine fuel mix etc). If it remains steady, low or high, it means it is dead and should be replaced. I had this exact issue way back on my 986, the porsche shop didn't know what to do and suggested to replace the converters. Car didn't pass inspection due to bad emission values and sometimes a CEL would appear, car ran just fine though. After doing some logging of my own and replacing a faulty o2 sensor the car was good to go; passed emissions and no CEL. So my advice - log the O2 sensor voltage before you spend money on converters you might not need. :cheers: