CODE P0421 and P0431
 

I have these two codes, P0421 and P0431, on a 2000 A6 Avant. Are the catalytic converters warranteed separately somehow for a longer period than the car? Or is there another repair that can be tried before replacing the converters?

RE: CODE P0421 and P0431
 

Clear the codes and see if they return.

RE: CODE P0421 and P0431
 

They do return usually in a day or two. This most recent episode was this week. I had the codes reset on Thursday, they returned on Friday morning after driving only about 15 miles.

RE: CODE P0421 and P0431
 

converter warinty is 8 years and 80,000 miles.
Try running the BG induction cleaner through. ( you need to find a shop that sells BG services)
MY friend did and the codes never came back, it seems the cleaner cleaned out the cats also.

RE: CODE P0421 and P0431
 

Thank you. I will look for a shop that does that.

I am beyond the mileage limit for the cat converter warrantee: too bad.