check engine light
Thread Starter
Pro
Joined: Jan 2003
Posts: 528
Likes: 5
From: Templeton Ca
check engine light
Yesterday the check engine light came on . I checked the codes and found these two
p0420 H C - twc system low efficiency bank 1 , I know the H is for History , what is the C for ? And more important what is the twc system?
second code
P1431 H - fuel level sensor 2 circuit performance , this one probably came up when we almost ran out of gas !
The car seems to run fine . Oh, by the way , its an '02 vert auto
p0420 H C - twc system low efficiency bank 1 , I know the H is for History , what is the C for ? And more important what is the twc system?
second code
P1431 H - fuel level sensor 2 circuit performance , this one probably came up when we almost ran out of gas !
The car seems to run fine . Oh, by the way , its an '02 vert auto
Race Director
Joined: Jan 2002
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From: I love you & miss you Linda
2017 C7 of the Year Finalist
St. Jude Contributor
The "C" means Current. That code was thrown very recently and with both H & C showing, the Current reading is not the first time the car has had reason the show that code.....
Do you have hi flow cats???
TWC = Three Way Catalyst
Do you have hi flow cats???
TWC = Three Way Catalyst
Last edited by Glennm27; Feb 18, 2007 at 02:03 PM.
Thread Starter
Pro
Joined: Jan 2003
Posts: 528
Likes: 5
From: Templeton Ca
Thanks, I read that the 420 code is for the "three way cat system on the drivers side . I crawled around as best as I could and cant find any damage . Where are the sensors located ? And , should I clear the codes from the DIC ?
Race Director
Joined: Jan 2002
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From: I love you & miss you Linda
2017 C7 of the Year Finalist
St. Jude Contributor
If you have hi flow cats, or no rear sensors after a header install, I imagine these codes would show up without the rear sensors being "written out" using LS1 edit.
OR a bad 02 sensor
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From: Home of the VOLS ! Knoxville, TN. Tennessee
St. Jude Donor '11-'12-'13, '15, '16-'17-'18-'19
if the car is totally stock . i would look at a Cat issue as well , not just sensors . if the cat is gone bad , then the values of the rear sensors would be close enough to the front ones that it would throw a code .
Been there with my LS1 Trans Am , replaced the Cats and the issue was gone .
Been there with my LS1 Trans Am , replaced the Cats and the issue was gone .
Drifting
Joined: Jul 2005
Posts: 1,533
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From: az
if the car is totally stock . i would look at a Cat issue as well , not just sensors . if the cat is gone bad , then the values of the rear sensors would be close enough to the front ones that it would throw a code .
Been there with my LS1 Trans Am , replaced the Cats and the issue was gone .
Been there with my LS1 Trans Am , replaced the Cats and the issue was gone .
if you are getting that code your o2 is fine, it is your cat is done (since your car is stock) replace the cats or get it edit out or o2 sims which is the cheapest way. good luck.
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