P0430 Chevrolet - Changed both O2 sensors and Cat

Question

I first replaced both O2 sensors and cleared the check engine light. In a short period of time the P0430 and Po420 codes came back. I replaced the Cat and cleared the error. In a very short period the P0430 error came back. Should I change the O2 sensor again or is there something else to try?

Answer 1

Hi there,

I wouldn't suggest you replace the sensors again, but check for other issues. Here are lists of all possible causes for these codes. 

P0420 CHEVROLET - Catalyst System Low Efficiency Bank 1

Read more: https://www.autocodes.com/p0420_chevrolet.html

P0430 CHEVROLET - Catalyst System Low Efficiency Bank 2

Read more: https://www.autocodes.com/p0430_chevrolet.html