Gmoney32

Hello everyone! I have a 2004 LX470 with 209k miles currently. Bought it 6 months ago with CEL/P0420 code and debated on getting exhaust replaced. Found a guy that could get me Lexus parts (with O2 sensors) for both sids much cheaper than dealer pricing... anyway, he replaced all O2 sensors and cats on both sides. It runs great, but the P0420 keeps coming back. I reset it with my code reader, and it stays off if I'm driving it for a while, highway trips, longer continuous drives, etc. But as soon as I start driving short trips and turning it off and on the CEL comes back on.

I heard somewhere that it would take 15-20 starts/trips before it would clear itself, just can't imagine why it won't stay cleared with (mostly) all new parts.

If anyone has experience or advice I'd love to hear about it... the truck is fantastic.. my 4th LC/LX and this is my favorite.

Thanks for any help you can provide.