Question

On my 2003 Pontiac Vibe, is the P0420 engine code the converter or O2 sensor?

Answer 1

HI there,

This code is for the catalytic converter on bank 1. If it's the 4 cylinder engine then it's the converter that is situated between the 2 O2 sensors right off the exhaust manifold.

Answer 2

P0420 PONTIAC - Catalyst System Low Efficiency Bank 1
Read more: https://www.autocodes.com/p0420_pontiac.html