Check Engine P0421
02-24-2011, 08:31 PM
#1
Audi Forum - Posts like an A1
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Join Date: Jan 2011
Location: wilson, nc
Posts: 7
Check Engine P0421
I had 2 catalytic converters replaced by the dealer in September on my 2003 Audi A6 when I bought it. Just the other day my check engine light came on and the code that came back was P0421, which is Pre-Catalyst. My mechanic told me this could be anything from readiness monitors to the actual catalytic converters (which are still under warranty luckily). Anyone had any problems with this code in the past and what I might could expect. He told me he could run some tests but he's booked until a week and a half, but that I should have no problems driving it until then. Any help would be appreciated.
02-25-2011, 07:05 AM
#2
Audi Forum - Posts like an A1
Join Date: Nov 2010
Location: Turner Valley
Posts: 11
Re: Check Engine P0421
I had 2 catalytic converters replaced by the dealer in September on my 2003 Audi A6 when I bought it. Just the other day my check engine light came on and the code that came back was P0421, which is Pre-Catalyst. My mechanic told me this could be anything from readiness monitors to the actual catalytic converters (which are still under warranty luckily). Anyone had any problems with this code in the past and what I might could expect. He told me he could run some tests but he's booked until a week and a half, but that I should have no problems driving it until then. Any help would be appreciated.
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View topic - 2003 Audi A6 P0421 Diagnosis
I just replaced my cat on my 1999 A6 and it worked. The cat rattled when starting the car so I knew where to look. It will be the driver side cat.
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