Hello all,

I've picked up a 2002 Sport Quattro 3.0 a few weeks back and have a couple of problems with it. I've had a search round the forum but if anybody can shed some light I'd really appreciate it.

First off I am getting a CEL, it's for code [P0421 Warm Up Catalyst Efficiency Below Threshold (Bank 1)] So far I have reset the light, driven for a couple of days and it came back. I changed the plugs, reset the light and have driven for two weeks. Now it's back on...

It seems to come on after long periods in traffic, low revs and stop start. The idle running of the car is also not as smooth as I think it should be.

I'm thinking O2 sensor maybe next but does the pre or post cat one go, or should I look elsewhere first?


Second Problem is a clunk in the transmission, feels like a gearbox mount needs replacing or something similar. Is there a common bush/mount to wear on these?


Thanks in advance.
Paul

 

Just guessing but have you checked plugs and ignition coils. I have 3.0 liter quattro and when there was problem here, even with just one coil, engine was awful until corrected. If someone has been under your hood much this problem could be compounding your diagnosis.
Good luck, 3.0 should run real smooth if all things proper.

 

I think that's definetly a bad Catalityc converter. Bank 1 only though, I don't know which one is which -after reading the formums : https://www.audiforums.com/forum/sho...ighlight=P0421 the bank one should be on the driver side for you since your car is RHD, and you could check your O2 sensors but I really think is your Cat. Is your transmission automatic or manual?

 

Yeah I was kinda hoping it wouldn't be the cat, although the code points to it...

I've knocked the light out and it's stayed out for the past two days... I'll try not to idle it in traffic for too long. I think a replacement of both will be on the cards at some point.

The transmission is manual 6 speed. It seems to have play somewhere, take up from the clutch then leaves a slight jolt after. Seems like a bush or transmission mount. Is this common?

One more thing, are the front anti roll/sway bars prone to wearing on the bushes or drop links? It seems to clunk on a tight turn at speed, in situations where the bar would come under tension.

Thanks all.

 

If there was a problem with a coil pack wouldn't it throw a code?

 

How many miles on the car? If it is cat converter, the warranty for it is 80k miles I think.

 

/\/\/\ I don't know if that warranty/law applies to him since he's on England...

Yes, it would read a missfire code.