C chrismarshall New member Joined Mar 17, 2013 Messages 4 Reaction score 0 Points 0 Mar 31, 2013 #1 My 03 envoy keeps giving me a code of 420. Cat system bank 1. Could be a few things to find the problem. Any help to start checking? Thanks in advance chris
My 03 envoy keeps giving me a code of 420. Cat system bank 1. Could be a few things to find the problem. Any help to start checking? Thanks in advance chris
