Im working on a 1997 explorer . Getting a code po420 catalyst efficiency below threshhold (bank 1). Can anyone tell me what this means. And a possible troubleshooting route. Cleared code and has'nt came back yet.

 

Rrbird57, see the post below, "code 420".

I believe you have a bad catalytic converter on bank 1. If you don't have any other codes in memory, it's hard to say what caused it. Apparently what caused the cat to degrade has been fixed, and the code was cleared.

You can either replace the cat, or wait to see if the P0420 code returns......