'99 Jimmy with P0420 TC - Catalyst System Efficiency Below Threshold (Bank 1)

[JimmyDied]

Hi all,

I have a '99 Jimmy that just tripped the SES light. The code was a P0420 - Catalyst System Efficiency Below Threshold (Bank 1). I can hear a loud rattle at the Catalytic Converter, so I am pretty sure it is hosed. It has about 120k miles on it...so I think it is about time to be replaced. Anyone have any suggestions as to what all to replace or how much it should cost??? Should I go for the whole exhaust system, or just cut out and weld in a new Cat?

It is my wife's car, so she is going nuts bugging me about it. How serious is a problem like this?

Thanks,
Damian

[drdd]

I replace the PCV valve (2 minute, 2 dollar problem) and it cleared the catalyst system effieciencty code plus three others !!!

[BlazerLT]

Originally Posted by drdd

I replace the PCV valve (2 minute, 2 dollar problem) and it cleared the catalyst system effieciencty code plus three others !!!

Sorry bro, but changing your PCV valve will NOT fix a broken cat convertor.

JimmyDied,

Replace the can with a universal replacement.

Should cost about 250 or less installed.