P0420

[Gg05]

Hey guys, I have a code P0420 on my 2005 Avalanche. Looks like it could be a numerous emission issues. Any ideas how to narrow down what it is?

 

[BainMan]

Do you have a scan tool capable of graphing or logging data? Start by logging pre & post catalytic converter o2 sensors (B1S1, B1S2, B2S1, B2S2). Post up the results at idle and around 1500 rpm.

Also, check fuel trims and misfire data, looking for reasons that the catalytic converter may have failed.

 

[ygmn]

P0420 Chevrolet: Code Meaning, Causes, Symptoms, & Tech Notes (With Video)

A 3-way catalyst controls emissions of hydrocarbons, Carbon Monoxide (CO), and Nitrogen Oxide (NOx). The catalyst within the converter promotes a chemical

www.engine-codes.com

google is your friend

 

[Gg05]

Do you have a scan tool capable of graphing or logging data? Start by logging pre & post catalytic converter o2 sensors (B1S1, B1S2, B2S1, B2S2). Post up the results at idle and around 1500 rpm.

Also, check fuel trims and misfire data, looking for reasons that the catalytic converter may have failed.

Thanks BainMan