Celica Forums General Discussion General Check Enginne light!

has been acting weird. It comes on, then off, then on...

I got the code pulled @ Autozone: P0420

This is what I found here https://celicahobby.com/ubbthreads/thread.f_1870112628_0_collapsed_2__1.html
CEL - Diagnostic Trouble Code Chart

DTC No. : P0420
Detection Item:
Catalist System efficency below threshold (bank 1)
Trouble area :
- gas leak in exhaust system
- open or short in heated oxygen sensor circuit
- Heated oxygen sensor
- threeway catalyctic converter

Is this a serious problem? what should I check first?

beats me bro

help right here:
https://celicahobby.com/ubbthreads/thread.f0_1953270050_2_collapsed_5_365_1.html#1953270050

dude you should try to check the cat o2 sensor i had that problem a while ago. is your making any noise?

Isaac just had that problem. Toyota replaced everything under warrenty, because of some laws in Cali. Go to Toyota and have them check it out.

I think the problem was the rear O2 sensor on the exhaust after the cat. But I don't remember, anyway, check with a dealer.

haha heather that avatar of your is hilarious...


oh btw...Morris is a girl...for those who didn't know.