I've read 9,000,000 different explanations for this code and I was hoping you guys could help me nail it down before I start throwing parts at it. The car has no driveability issues and doesn't seem to be down on power. Only problem is the damn CEL. How likely is it that the cat is fouled at 133k? I've also read that it could be either the primary or secondary O2, clogged EGR port, etc... What's the cheapest/smartest way to start going after this problem?

 

likely. you can try scotty kilmer's tips: http://www.youtube.com/watch?v=5icTmYItwiE

or just replace it outright. see this thread for my tips:

https://honda-tech.com/forums/honda-accord-1990-2002-2/99-accord-code-p0420-cat-conv-need-help-3068452/

 

I had this code once and i threw a new universal secondary 4 wire sensor on it and have been good since. Glad I did not buy a new cat.