I seem to be running into some issues with my car passing emissions test.. Car is a 99 A6 quattro 2.8 v6. Currently reading codes:

P0432 and p0422 main catalyst below efficiency threshold bank 1 and 2

P0411 secondary air injection incorrect flow

Anyone have any ideas on if the 2 are related? The cats were replaced about 2 years ago with magnaflow universals, after oems both went bad. Rear 02s have both recently been replaced.

Thanks for any input!

 

The rear O2s are the common point - they measure both cat efficiency and SAP flow. If you've replaced them, did you actively clear the codes afterward? Do you know for sure that they're new codes and not leftovers from some time in the past?

 

One other thing to do is to check your vacuum line. A broken vacuum line can cause P0411. Also P0411 can cause the converter codes.

 

I cleared the codes after replacing the o2 sensor, and this code came up 3 or 4 days later.

I'll have to check the vacuum lines, as I have noticed a loud air blowing noise coming from down where the secondary air pump is.

The thing I'm trying to avoid is buying new direct fit cats (as I've heard the universals like I have, have a tendency to throw this code) and then find out it was something much cheaper... Is the secondary air pump pretty common for causing a catalyst below threshold code?

 

SAI pump does not have any vacuum line connected to it. Anyways, I would fix that issue first. It may get rid of your catalytic converter codes.

 

Sorry, bringing this back from the dead... So i found a broken vacuum line, which fixed the secondary air pump code. Now im just down to the p0432 and p0422 codes. The cats are aftermarket universal cats but they don't have any rattle so i don't think they are the issue.

Ive read several places online that there is a computer reflash that may be needed as the o2 values are too stringent... Does anyone know if that's correct? i called a local dealership but the tech i talked to acted like he had no clue what i was talking about. If anyone can advise as to whether or not these claims are true, that would be awesome!

 

A coworker of mine had that done for $100 on his Passat at the dealer and no longer has cat efficiency codes popping up.

 

Yes 2.8 had an update that remedied the catalytic converter threshold.