so my check engine light has never come on until after my rear end went out and i had it replaced-not sure if that has anything to do with it but the first day after it got fixed the light came on. now the strange part about this is that the light only comes on occasionally and the even weirder part is that it only seems to come on when im sitting at like a stop light for a period of time..then when i start driving again the light goes off. any ideas???

 

How about reading the codes?

 

well the auto part store only has a code reader for the years 96+ so that doesnt really help me

 

First guess is that while repairng the rear, the exhaust may have been knocked around some and there is now a loose connection at one of the sensors.

 

They have code readers for OBD1 at O'reillys Auto parts, try this link to find a store near you.

http://www.cskauto.com/

 

and this would cause a check ENGINE light? interesting.



can they still read codes when the engine light isnt on?

 

If it has been reset no it can't. But if it went off by itself without resetting it should.

 

yeah it goes off by itself, the second i hit the gas after being stopped. it hasnt done it yet today and yesterday. its really random

 

The check engine light can come on for a wide variety of reasons, essentially all of them having to do with emissions. There are sensors in the exhaust system. If damaged or shorted, yes, the light could come on.

 

It also comes on for rear ABS too.

 

You don't need any scanner to read EEC-IV (pre-'96) codes; a paperclip is enough. Read this & follow the links in the caption:



The thread linked there explains what happens when the light comes on, and yes, there are many codes that don't turn the MIL on. The ABS has a separate light, and a separate procedure for getting codes.