I'm at 63K right now and got my CEL scanned today and it is the P0430 code. I did a search and it seems to be failing catalytic converters. I talked to a Lexus tech at work and he said to replace my O2 sensor first. So how can I test if it's a bad O2 sensor or if it's a bad cat? I do have an intake, deleted secondary cats, and exhaust but never have I touched the cats.

 

Can be multiple things. O2 sensor, bad cat, exhaust leak... Hope this helps: http://www.obd-codes.com/p0430

 

The tech is a moron! Take your car to a muffler shop and have them preform a catalytic pressure test. This will tell if the cat is clogged or not.