2002 Chevrolet Trailblazer P0420 and P0300 Codes: Causes and Solutions

Model: Trailblazer Fault Code: P0300 Posted: 2006-05-25 19:14

I'm currently experiencing both P0420 and P0300 diagnostic trouble codes on my 2002 Chevrolet Trailblazer. The vehicle runs fine under normal conditions, but I notice a slight idle hesitation or skip. I suspect either a faulty oxygen sensor or a failing catalytic converter. I replaced the exhaust manifold oxygen sensor three months ago due to a previous code, and now I'm seeing these new codes. Given that the truck is still running smoothly otherwise, what could be causing this? Are there any common issues with the 2002 Trailblazer related to these codes?