For kick and giggles, I decided to attach my OBD 2 reader to the port on my GX. To my surprise, I found a P0420 and a P0430 code on my truck. What's really weird is that I don't have any CEL lights on. I went to a muffler shop to see if the cats are actually bad and they told me right now they weren't. What should I do? Wait till the CEL comes on or replace the O2 sensors.
