Check Engine light comes on and off when ever it feels like it !!!

[Mafiozi]

Hi,

Very vague question. Got a 91 conv GT with only 20k miles manual trans, and I noticed the check engine light comes on sometimes when it feels like it, especially after the engine got warm. It happened 3 times already and I couldn't get it to the shop when it came up cause it happened on a sunday, but once it came up on a weekday but the light turned off after a minute or 2. Went to several shops and they said I must bring it in when the light is on and only on, WTF isn't the code stored in memory??? HELP !!! Thanks in advance.

 

[TBapp3]

I always check my codes at AA....But as you said I believe the light needs to be on in order to check...

 

[1990_LX]

My mom's GT was doing that. I took out the MAF and IAC and cleaned them and it runs a ton better and the light is gone. There could also be a carbon build up on the 02 sensors.

 

[93FiveOh]

+1 , check the easy shit first. seems like a dirty sensor

 

[vorstang]

most likely a bad o2 sensor

 

[PJB]

Mine did that when I bought it and it was a dirty evp sensor (part of the egr). I cleaned it and the light has stayed off ever since.

Ive since deleted the whole egr system.

 

[dsblk93gt]

It will not store the code all the time. It could be just about anything. Any sensor could cause it honestly, especially with the low miles the car obviously sat a lot. I really would not worry about it too much.

 

[bulldog107]

Mine did that too but only upon acceleration.I cleaned the egr and it fixed it,then I did the egr delete and it went away for ever!!