tguaturbo

I've been getting "Post catalyst fuel trim too rich bank 1 & 2 at different times, I think it's P2097, P2099. I get the code about every 1-3 months and just clear it and see how long it takes to come back. Today after changing my battery and driving for a few minutes while the car was standing still but on, I got P0430/P0420 "Catalyst system efficiency below threshold bank 1 & 2.

Last Oct the car got: New plugs, coils, o2 sensors, serpentine belt, fuel filter and maf sensors. The car has 45-46k miles and it has an AWE exhaust and cats.

Is it safe to say my Cat's are needing replacement?

Pclemg01

Typically, those codes results in needing new cats and o2 sensors. You should have it check out to verify. Sorry to hear that on you car. Cats don’t usually fail that early. I don’t have a lot of experience with Porsche yet, but own a auto repair shop and see it happen often with vehicles over 100k miles

Steve 96C4S

Not sure about codes or anything like that but your P0420 code is very similar to my license plate on my last Porsche. PCA 0420. Kids used to come up to my car and ask me if I had any pot. I'm so out of touch, I wasn't even sure what they were talking about for a year.

Watson

Hi

P0420 means you need to replace your catalysts as mentioned by others before.
it does not necessarily mean that your O2 sensors have a problem.

When you remove your cats, it would be interesting to check whether the bricks have been damaged (melted or collapsed). P0420 are caused by too high exhaust temperatures which will damage the catalyst bricks. The real difficulty is to identify why these high temperatures occurred. Did you observe any issue of misfires lately?