Naonak

I believe I have failing cats on my 2011 Cayenne S. I've tried searching the forums, but since the word CAT is so short, searches are useless, and nothing comes back relevant for catalytic. If a thread already exists, I would be grateful for a link.

That said, I am looking to just either bypass the primary cats (not the secondary!), or put a standoff on the downstream sensor. I just want the CEL to go away, that's my goal.

Is there a guide to location/access, and is the threading standard on the Cayenne S that I can just use a universal standoff? As I understand it, there's 2 primary cats, so I'll need to do both sides?

Is there any suggestions anyone has for taking care of the CEL with least amount of effort and cost? Error codes are P0431 and P0421

Thanks!

jtakhtalian

What's the mileage. I'd suspect oxygen sensors before concluding the catalytic converters are bad. Also, the primary cats are the ones that do most of the work and it's where the main oxygen sensors feed information back to the emission system and dictate whether the car runs lean or rich. Basically, the engine control system uses this data as a fundamental piece of the information to manage the car's operation. Not sure bypassing the primary cats to get rid of a check engine code is going to work the way you think. One more thought would be to to try and run some cataclean through the fuel system to see if it changes anything. I'm not a huge believer of miracles in a bottle but some of these things actually work for a period of time when used exactly as directed.

Naonak

The car has about 100k miles on it. The car isn't near me, but I've had it at a garage that says the cats are bad. Whether or not they are is a mystery, of course, and I have no reason to distrust the garage, but I have no reason to trust them, either. I'm going to have the car shipped back to me (about 1000 miles) to resolve the issue and do the brakes, since between the two issues, they want over $5k to fix... haha...no. I'll do the work myself, thanks!

I'd be fine running catclean through it, but I've never seen it work personally... but even if it did, I suspect the problem would return sooner or later and I want to resolve the issue permanently. I don't want to have to deal with the cats again for the rest of the time I own the car. If the standoff isn't going to be a solution (worked for other cars, though, for me?), what's the quickest, cheapest solution to resolve the issue permanently? Bolt on cat bypass pipes, of course, but it still leaves the CEL issue, so I'm not seeing that as being a solution. I'm open to an ECU flash to remove those codes completely, but I don't know of anyone doing that on the cheap - everyone wants like $1000 for an entire tune, which I don't really need.

RAudi Driver

Aren't cats warrantied for like 100k

Naonak

I thought it was like 70k? My car is still under 100k (just barely) so if it is 100k that'd be great, but it's Porsche, so I doubt it.

deilenberger

Emission components - like CATS and sensors are covered in the US by a federally mandated warranty, The warranty booklet that came with your Cayenne will explain what it covers and for how long. Basically - it's 8 years and/or 80,000 miles, whichever comes first.

Some states have mandated additional warranty coverage - you'll have to GOOGLE for your particular state.

Naonak

When the error codes are for Catalyst 1 bank 1 and bank 2... what are we talking about here?

Which cat is cat 1? Right or left?

And bank 1 and bank 2 are referring to what? Are both of those the down stream sensor or is one the upstream sensor? I'm trying to figure out what the best course of action here is.

kennyt

Don is correct. Had my HPFP replaced by dealer under the 8 years or 80,000 miles warranty as it's emission related component.

Naonak

Yeah I am way over my 80k miles so I need to figure it out myself unfortunately.

deilenberger

The "bank" is the group of cylinders sharing a cylinder head, ie - the 4 on the starboard side of the engine and the 4 on the port side. For a person standing looking into the engine compartment from in front of the vehicle dead center - the bank your left hand can reach is BANK-1, That leaves the bank your right hand can reach as BANK-2. And that long explanation is why I prefer port and starboard, just like on a boat - these never changed. Port is aways the port side and ditto on starboard. In this case - starboard side is bank 1, port side is bank 2.

The #1 and #2 cats is because each exhaust branch has two catalytic converters in it. The one closest to the engine is #1, leaving the other one to be #2;

Naonak

Thank you for the explanation, that was very helpful.

So in my case, can you clarify that this means there is a problem with the catalysts on both sides, port and starboard? And if that is indeed the case, that would seem to rule out sensor failure, yes? Given the mileage, what are the chances they both failed within 2 weeks of each other? My understanding is that it would be slim and the cause would be an upstream failure somewhere sending gunk into the cats, yes?

I recently had the plugs and ignition coils replaced, and I had the dreaded coolant hose glue failure that was fixed about 4 months ago. No other error codes are popping up. Any suggestions would be helpful.

leftlane

We had the same CEL come on at 99k miles on our Infiniti after something banged under the car while driving. I reset the code with a handheld reader and it hasn't come back in 6k miles. Can you reset the code and see how long before it reappears?

Caliguy

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