2005 Chevrolet Trailblazer, changed all parts for the P0420 code engine light still ON

Question

2005 Chevrolet Trailblazer 4.2L, changed all parts for the P0420 code engine light still ON

Answer 1

Hi there,

This code indicates an issue with the catalyst system. Here is a list of all possible causes for this code.

P0420 CHEVROLET - Catalyst System Low Efficiency Bank 1
Read more: https://www.autocodes.com/p0420_chevrolet.html