I'm getting the trouble code. P0420 Catalyst Efficiency Below Threshold(Bank 1). What the hell does this mean? I've recently replaced the o2 sensors so im guessing my cats are getting screwy? What does this mean and how do i fix it? I've never delt with this trouble code before.

 

It's either a slow heating O2 Sensor or a Converter going bad on the drivers side.

 

More than likely your Cats have degraded beyond what the PCM would like to see. Depending on mileage, they are covered for 10/100 from the factory.

 

Brian is exactly right.......they will degrade over time...not just up and go bad. But you know...who the hell needs converters anyway?

 

Thanks guys.