Check Engine Light?

[philjw90SHO]

MY SHO's check engine light comes on above 85 mph and it goes out when I slow down. I just took an emisson test and I almost failed because I had too much unburnt fuel coming out of the exhaust. Is it a computer problem because thats what my suspicion is. Would it be cheaper to have a professional adjust the computer or just buy a new or used computer off ebay. Any help would be appriciated.

Thanks

 

[93nighthawk]

It sounds like your O2 sensors are shot. But without knowing the codes it is tuff to be sure. You can pull your own codes using a paper clip. Go to www.shotimes.com under care and feeding to see how. The Check Engine light comes on to tell you that there is a problem that needs attention. It is highly doubtful that the computer needs replaced.

Also, what year/transmision is your sho, milliage, that always helps in diagnosing. thumbs_u

Eric

<small>[ October 20, 2002, 10:59 PM: Message edited by: 93nighthawk ]</small>

 

[philjw90SHO]

I'm sorry about my description. i have a 1992 MTX with 105,000 miles

 

[Mike Kopstain]

It has been my experience on any car that computers don't just change variables. They work or they don't. What will change variables are sensors, and on a car that is this old a great deal of them could be giving innacurate information to the computer, causing your problem. Your first line of action is to read the codes from the computer. Look in my Signature for instructions. Besure to read the instruction carefully. There are a couple seperator pulses and test pulses that could throw you off.

~ Mike

 

[sdpatt]

Here is a re-post of a response I made to a previous discussion of the value of the CHECK ENIGNE light.

"The CHECK ENGINE light is not confusing, it is your beacon in the dark for analyzing engine control problems. It is your friend. Learn to read the codes. It only takes a few minutes.

<a href="http://www.dalidesign.com/hbook/eectest.html"" target="_blank">http://www.dalidesign.com/hbook/eectest.html"</a>

The only thing you'll need to run the tests are a short jumper to connect the SELF TEST INPUT to the SIGNAL RETURN terminals in the EEC TEST plugs and your ignition key. I always carry the jumper and the printouts of the code descriptions with me in the glove box. The links to the 2 and 3-digit codes are near the top of the page at the URL above. If your car is '92 or later, you will be looking for the 3-digit codes. My early '91 uses the 2-digit codes.

 

[SHODWN]

Eventhough the temp gauge in the car dont really mean shit, what does it say? is in on the cold side?

Most of the time stuff like this is cause by a stuck open thermostat preventing the car to get to operating temp..