Hey All....

I have a 996 C2 with 60000 miles on it.
Bought it under couple of years ago.
Seemed to have no issue at the time (as passed PPI by Porsche dealer with flying numbers).
soon after first routine oil change and a minor service (by Porsche dealer) had oil leak!!

Went back to the dealer right away.
They ended up saying that there is a leak and they need to bring down the engine to pinpoint the fault. As I had no choice agreed to their suggestion. After having the engine down, they said it was a small hose (worth 50 USD) that leaked the oil but as the engine is down, I might as well get other "consumables" replaced. So they go around changing some cables and pipes and assuring me that nothing further needed in foreseeable future!
Sure enough they pass on ~7000 USD bill.
As I bring the car out, it gives me CEL.
After few returns to them (back and forth as they initially just blamed it on OBD) they ended up saying that it was due to faulty Catalytic converters and they suggested to change them for me "if I want the CEL gone permanently".
The quote is pretty hefty!

the parts they are asking me to change:
996.113.031.BX -Catalytic Convertor-
996.113.032.BX -Catalytic Convertor-
996.606.178.01 (2 of these) - Oxygen Sensor-
996.606.168.01 (2 of these) - Oxygen Sensor-
900.074.287.02 -Bolts-


As you can tell, I am not that handy person as many of you guys are and have to trust the dealers blindly!
I am not sure as the part of the world I am at has little experienced (and honest) shops that I could trust outside the dealership.

As I am planning to keep the car for few years more -if I could- I was going to follow what you guys advice...
I have to say that with CEL on, I have not noticed any performance issues. If it was not for the CEL -that nags me every time I turn the engine on- and its reminder on the dash, I would have not bothered at all.
Also, as I m planning to move to another province/country, there is a bid chance having CEL would end up costing me to get rid of the car that I honestly love at this moment.

so,

1. Do you guys think that changing Cat Convertors (and other parts) is the way to go?
2. Cat Delete is an option, however I am not sure if the government annual check up would let me go through with that... also out of province inspections (in Alberta Canada) may also be a hassle.
3. if I have to, whom should I buy the parts from (who can give a reasonable -in quality and price- aftermarkets)?

appreciate your help in advance....

 

In this particular incidence, I don't think there was any manipulation on the dealership's part. Your car is 17 years and that's a pretty good life span for the cats. They were probably on their way out and the recent service is what pushed it over the edge. It was just a matter of time. There is always a chance it could be faulty O2 sensors, but more than likely, you'll need to replace the cats to get within normal operating range.

What did they quote you for new cats and O2 sensors?

Normally, a dealership will charge you a major arm and leg for this type of service. OEM cats are crazy expensive and so this might be something you want to tackle yourself.

 

What are the error codes? P0420/P0430 are converters operating below efficiency threshold.

Porsche says -- this from several factory manuals -- that if there are any active or pending aging O2 sensor error codes to replace the indicated sensors then clear the codes and road test the car. If the P0420/P0430 codes come back replace the indicated sensors.

Since the engine was just dropped I'd be darn sure -- the shop should be darn sure -- there are no exhaust leaks. I note the converters appeared to be working just fine before the engine drop. That the shop blamed the converter error codes on "OBD" suggests to me that the shop is not the sharpest tack in the box. Porsche via its factory manual for its cars is very clear on what steps to take to determine a converter is bad. Since the factory is on the hook for converters for 8 years, 80K miles -- this a USA federal emissions required warranty -- Porsche wants to be darn sure the converter is bad. There is no guessing. There is no "OBD" fault possible. (In the unlikely event the engine controller is bad Porsche is on the hook for that too.)

'course your car is out of the converter warranty coverage assuming there is even one for cars sold in Canada. Still doesn't change how a proper diagnosis should be done.

If the exhaust system is leak free and after clearing the codes and a road test of the car if just one or both converter codes come back this suggests the one or both converters are bad. They can fail at any time, but I have to tell you absent heavy track use -- which tends to run them too hot -- converters last a long time.

While I had to replace the converters on my Boxster I did so because one was damaged by an impact from road debris. The "brick" was knocked loose and occasionally it would get out of position and trigger a P0430 error code. After several years of an occasional P0430 error code, which was appeared even less often when I switched from using discount gasoline to using Shell V-Power and even though my usage of the car remained the same, and dealing with the buzzing when things got up to temperature, and a dull low knocking when the engine was cold, I sourced two converters for my car from a business that deals in salvage Porsche and the parts from the cars.

I picked up two converters -- exhaust manifold with the converter part of the manifold -- and shook them to make sure nothing was loose inside and rotated them this way and that to make there was no loose debris inside, which if there is can be a sign the converter is falling apart. Once I was satisfied the converters appeared to be ok I handled them like glass. The cost was $495/each, compared to over $1000/each for the factory converters.

A Porsche tech performed the swap and afterwards the exhaust was quiet, the P0430 never came back, and the car passed at least one smog check with flying colors.

My 996 Turbo covered 161K miles with no converter problems. The O2 sensors were replaced at around 132K miles when one's heating element failed.

So where does this leave you? To emphasize, you (the shop) must be darn sure there is nothing else that can account for the converter error codes. (I'm assuming they are the P0420/P0430 codes. If the codes are something else that can change things.) Specifically -- and I am repeating myself, but this is important -- the exhaust system must be leak free. As a side note whenever my Turbo had its exhaust system out for a transmission replacement, for a new RMS, for several plug changes, the tech always replaced some exhaust gaskets every time. I remember specifically metal "o-rings" that sealed the turbo to the exhaust pipe. He told me if these were not replaced the exhaust system -- at the turbos -- could leak. I'm not that familiar with the N/A 996 model but the shop should be.

If there are no other explanations for the converter error codes, then one I guess has to assume they are bad. I still have to point out it is rare for both sides -- I'm assuming both sides are generating error codes -- to go bad at the same time. One might fail at 60K miles which by itself is rather rare, but to have both fail at the same time, and with the engine just dropped... I'm sorry I'm just not buying it.

Deep breath. Ok I feel better now...

Assuming you are faced with replacing the converters then you can go with the factory setup. it will be an expensive repair. For my Boxster and this some years ago the quote for factory converters was over $1000/each side. The plus is they bolt right in, are of high quality, and look "stock" which if you have to have the car inspected for road worthiness or emissions this goes a long way to avoiding raising any eyebrows of the inspector.

They come with a warranty.

But they come with a high cost.

You can consider using converters obtained from a salvaged vehicle, ideally if possible from the same MY and even the same model as your car. That is if your care is a 996 then get a set from a 996, not a 996 4S or something.

There is the risk one or both of the salvaged converters is bad either bad when taken off the car, or rendered bad by mishandling. You can do the the shake test the rotating the converters around to make sure nothing falls out then handle with kid gloves. You won't know if the converters actually work though until they are bolted to the car and the car driven. The business I dealt with told me if the converters prove defective once on the car it would take them back for credit or exchange. 'course, I would have been out the labor cost, but this was not onerous. Fortunately the two converters worked just fine.

For USA cars there are non factory converters available for those cars that the factory converters are bad and cause the car to fail emissions. There are suppliers of converters that are recognized by the EPA and CARB as suitable replacements for factory converters.

Below is a link to the CARB site. Select make, model year, model, engine size and see what replace converters are available, the cost, any warranty, and whether they are bolt in or require something else to fit to the car.

https://ssl.arb.ca.gov/AftermarketParts/catalysts

Wanted to add the above assumes that what the EPA/CARB have decided is suitable for use in place of factory converters, that the Canadian vehicle emissions regulatory agency agrees, accepts. If not you then need to explore replacement converters that meet with the Canadian emissions regulations.

There are aftermarket exhaust systems some of which may be suitable for use. This assumes that they are recognized as legal/valid replacements for the factory exhaust. I have no experience with any aftermarket exhaust systems and I can't make any recommendation. I am not at all familiar with emissions testing/compliance rules in Canada but of course you must be in order to select a suitable replacement assuming there is one. With an aftermarket system there is the concern it can affect the exhaust sound in a negative way. Most often the complaint is the exhaust manifests a irritating "drone" at various engine/vehicle speeds. While at other times, the exhaust sounds ok even "great", the droning ruins the experience.

 

the dealership is quoting me something like 4000$!! for the parts only.....

 

THANK YOU for the illuminating and informative response....
This is the value of these forums. Newbies like me get an honest expertise opinion and advice....
I will save your words of wisdom and go through them few times and take the advice.....

once again very much appreciated the effort and time you took to get back on this matter.....

have a GREAT day man!

 

what am I chop liver? Lol 😂 Way to give Macster all the credit.

 

Not at all...
Actually you are the first one on the block to respond....

and as the saying goes on something like " first is better than....."
Your contribution is valued highly....



there... I redeemed my mistake.. right?