Mt check engine light came on yesterfay about 5 minutes into my drive....Went off about 5 minutes later. All the guages looked good and the car was running great. Any ideas? Thanks

A few years ago the Check Engine light would come on intermittently on my '89 mostly while on the highway during one hour commutes to work. Ran fine but the fuel mileage gradually started dropping. Went crazy trying to figure out what was going bad and finally was able to get the errror codes and my problem initially turned out to be the fuel pump. Installed a new one and problem came back about 6 months later and turned out to be the injectors. My vette has 150k miles on it so when I did the injectors, I addressed other things too like the EGR, thermostat, oxygen sensor. Anyway, that's how it unfolded for me, yours could be something similar or completely diff reason (other than driving ya nuts part lol).

forgot to mention, when the problem came back, the car started running awful, spit, sputter, no power and felt like a 78 chevy chevette

Thanks for the info. My vette has 46,000 miles and runs great....Wonder if I can take it somewhere and get them to read the code on the computer?

if you jump the a and the b terminals on the aldl, the codes should display by the speedometer.

joel, on my 90 the codes display next to speedometer where the inst average shows and where the miles you have left with the fuel you have. 89 and before flashed thru the ses light. 

YA...I knew dat, but...that's the only diagram I have loaded of the ALDL connector....  Mostly just showing which terminals to jump.

Had the same problem with my 95.  Turned out to be the EGR valve; I'd check that first.

Does anyone know if the engine check diagnostic service from Auto Zone, NAPA, O'reillys, Carquest, etc will work on our C4's ? And if so, is it good for some years but not for others?  I've taken a few vehiles from the early 2000's to our local AutoZone to get the codes read and it was great. But I'm wondering if this applies to our Vette's ?