I have been recently getting a P0421 code and am looking for idea of what it could possibly be? I have a stock downpipe with a CS Race pipe. I could only find posts about this code when people have an aftermarket downpipe installed.
Could this be because it started to get cold around here? I doubt it is my Cat or the O2 sensors going bad but let me know what you think.
Opinions are appreciated. Thanks.
Could this be because it started to get cold around here? I doubt it is my Cat or the O2 sensors going bad but let me know what you think.
Opinions are appreciated. Thanks.