99 WJ Error Code...

Chad Fraker did pass the time by typing:

The downstream O2 sensor is telling you it thinks the catalytic converter is not doing its job.

Either the sensor has drifted or your catalytic converter needs attention.

Sorry to hijack the thread -- My cat was shot, but the sensor never said anything. Would that mean the sensor is bad?

Eric

Right...so I am not mechanically inclined beyond simple fluid changes. Can someone give me a hint on what this might mean? Just spent a bunch of $ replacing CPS and about 2 weeks later we get this code:

P0420 (M) Catalyst System Efficiency Below Threshold (Bank 1)

Catalyst 1/1 efficiency below required level.

Chad

99 WJ Hers