Strange O2 Seneor Question?
Strange O2 Seneor Question? 
TECH Senior Member
Joined: Dec 2001
Posts: 5,399
Likes: 3
From: Jacksonville, FL
It'll probably throw something else first, since the rear 02's need to be working to report cat inefficiency codes. Don't know what code will show up first, but there are codes for insufficient activity/heater performance/circuit low voltage........
Thread Starter
Staging Lane
Joined: Jun 2009
Posts: 70
Likes: 1
hmm I replaced both downstream O2 sensors because i was getting a P0420 and a P0430... I got the P0420 code again - meaning that the CAT is bad... But I have not got the P0430 again. I am sure it will come back soon...
The dealer is going to replace the P0420 CAT but said that would not replace the other because there was no code.... Guess I should not have cleared it the first time
The dealer is going to replace the P0420 CAT but said that would not replace the other because there was no code.... Guess I should not have cleared it the first time
TECH Senior Member
Joined: Dec 2001
Posts: 5,399
Likes: 3
From: Jacksonville, FL
Yeah, always good to leave the codes active when visiting the dealer for warranty items. How long has it been since the P0430/did you just clear the current code or reset the PCM? Most stay in history for 40 ignition cycles - maybe it's still there? I'd ask them to check the passenger side anyway.
Thread Starter
Staging Lane
Joined: Jun 2009
Posts: 70
Likes: 1
The people at the "stealership" are nuggets. They wont even talk about replacing the CAT if there isnt a code... And it is gone. 
I cleared it.
Maybe I will bang on the Cat with a hammer and get it to mess up.. lolz
I cleared it.Maybe I will bang on the Cat with a hammer and get it to mess up.. lolz
. Then I will have to go back to the stealership a second time. 
