Hi,

I remember I while back I had a diagnostics run on the TL and it showed a P0420 code...but my check engine light never came on. I'm at 74k miles at the moment.
I was wondering if I should do anything with this error?

Nick

 

P0420
67
Catalyst System Efficiency Below Threshold


here is what I was able to pull up. Looks like your catalytic converter might be done with.

 

Service Manager said that if the cat was bad it would trip up the engine check light. I have not seen this yet...he said it might have been when the diagnostic was run that the car was not warmed up yet...which may be true.

But he said since the engine check light is not on, there is nothing to worry about...

Oh well...

 

Check out this thread.