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P0421 Diagnostic Trouble Code Discussion for March 2009

Warmup Catalyst Efficiency Low (Bank 1)

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Trouble Ticket Help Requests for DTC P0421
Help Request Posted
2001 Audi A6 Quattro 2.8L cel VIN: WAUEH64B11
P0421: 16805 Warm Up Catalyst Bank 1 efficiency below threshold. ... reading this. This vehicle came in with a CEL for converter warm up efficinecy below threshold (both banks), light has been on for about a year. O2 sensor signals do not appear lazy. Codes apply to the primary converters right off the manifold, flow of dia...
March 25, 2009
2003 Audi A6 3.0L MIL Lamp on VIN: WAULT64B63
P0421: catalyst inefficient. Looking for some repair info on what needs to be removed in order to replace the catalytic converters. All data has no repair info. Labor shows 5hrs. Do I have to remove the subframe? Any help would be greatly appreciated before I quote the job. Thanks.
March 26, 2009