Check Engine Light
Thread Starter
Instructor
Joined: Jun 2007
Posts: 111
Likes: 1
From: Huntsville AL
Check Engine Light
I just purchased an 81 a few days ago and noticed today if I let it sit and idle for 5 minutes or so the Check Engine Light comes on. After driving for a minute or so it goes off. What could this be and where should I look to resolve this?
Thanks in advance for the help.
Thanks in advance for the help.
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
Thats probably the O2 sensor telling the computer that the fuel mix is off and it can't compensate for it. The carb will need some adjustment. You need to aquire a shop manual on that year vette, get the GM reproduction one, it has troubleshooting guides for the CCC system. You will then need to "Read" the code by jumping a plug under the ashtray and watching the light flash. It will flash a set of numbers to tell you what the error code is.
Race Director
Joined: Sep 2001
Posts: 10,560
Likes: 439
From: Wellington, FL
St. Jude Donor '11 thru '25
Thread Starter
Instructor
Joined: Jun 2007
Posts: 111
Likes: 1
From: Huntsville AL
Thanks for all the input. I thought it was may have something to do with the O2 sensor and, I forgot to mention that the catalytic converter was removed when the mufflers were replaced so that makes sense. It's no big deal really as long as nothing harmful to the engine is happening.
The code list will be a big help confirming thr O2 sensor if that is indeed the cause. Next question... how do I get a readout of the codes. I understand the connection is under the ashtray???, but I'm a newbie owner and not familar with the diagnostic techniques for Vettes. I can turn a wrench or do anything necessary mechanically or electrically if I know what the issue is.
Again, I appreciate all the suggestions. This site is a tremendous resource of knowledge from a bunch of super nice folks.
The code list will be a big help confirming thr O2 sensor if that is indeed the cause. Next question... how do I get a readout of the codes. I understand the connection is under the ashtray???, but I'm a newbie owner and not familar with the diagnostic techniques for Vettes. I can turn a wrench or do anything necessary mechanically or electrically if I know what the issue is.
Again, I appreciate all the suggestions. This site is a tremendous resource of knowledge from a bunch of super nice folks.
Burning Brakes
Joined: Feb 2000
Posts: 1,246
Likes: 1
Sounds like the car jumps out of closed loop because the O2 sensor isn't heated up enough @ idle. This is a common issue when re moving the cat. The cat creates tremendous heat and that's why the O2 sensor is placed there in close poximity. Either use a heated one or move it upstream.
