Hi new to the forum. My 2007 caliber engine light came on at 88k. The code p0420 came up on the scanner. I changed out both O2 sensors and after a short drive the light came on again with the same code? Am I going to have to change the cat?

 

Splicer,

It is possible that a Cat may be needed. Below are the possible causes of the p0420 code.

EXHAUST SYSTEM LEAK
ENGINE MECHANICAL CONDITION
AGING OR CONTAMINATED O2 SENSOR
O2 SENSOR WIRING AND CONNECTORS
CATALYTIC CONVERTER

 

Welcome to the forum. Check the owners manual and see how long the emissions warranty is on your car. Some are pretty long.

 

Thanks for the replys