[ck25]

I have a 2004 corolla w/ 135k and the check engine light has been on recently throwing the same code. This weekend I replaced the cat with one from the manufacture of "Walker" from a local parts store. Little bit of elbow grease involved, however so far it has seemed to take car of the p0420 code at this time.

If you are a weekend DIY with mechanic tools it really wasn't too bad. about a 2 hour job... 1/2 hour of that was spent getting the car up on 4 jack stands.

It is crazy what the dealer wants for this replacement.$$$$$$


I had an O2 sensor go around 90k (bank 1) and I believe the code at that time was something different. However from the research I have done the Po420 code doesn't necessarily mean the cat is bad. I've read other sites where individuals have replaced the cat and the p0420 code still exists???


good luck