The code states: The pcm has determined that the catalyst system efficiency for bank 1 is below threshold for the current engine operating conditions. I do have a hi-flow cat, which has been on for 6 mo now-magnaflow btw- and the CEL came one last nite. I didn't find any leaks on the exhaust though. The car drives fine, I didn't notice any difference.

What could it be? Or what else can I check for?

6 mos is about when the Kronium in a hi flow cat quits. Sounds like the down stream O2 Sensor is telling you the cat isn't working.


Tach Out Motorsport
Http://www.team-tachout.com/
Falmouth,VA

Does that mean that I have to replace the CAT?

after market cats are notorious for this you could try an o2 sym

oh yea I didn't even think of that.............thanks jon