I did a ton of work on it last year. New MAP, and Ignition Module, new O2 Sensor. New distributor. Its been running great. Took it on a 70 mile ride yesterday and on the last leg the CES light came on.
After I got home. I turned it off and then back on and the CES light didnt come back. Its early the next day and I havent checked yet for codes. Any suggestions as to what to expect?

It did this a few times last year before I did all that work and before replacing the catalytic converter. I have smog due next February so I have a year to figure this out. There was no change in the engine after the light came on.

 

could be many things. You need to check for codes. It's incredibly easy you can use a paperclip.

 

I know. No codes. I thought once the light went out. Codes are not stored.

 

They are stored in OBD-II systems. Not sure about OBD-I but it's worth a try.
Otherwise you'll have to wait for it to come back.

 

Iam more familiar with the OBD2.I "think" what "may" have happened is the vacuum hose to my EGR valve slipped off. My old-school egr valve had a brass port to attach the hose. I needed to replace it a couple of years ago and the new one came with this plastic swivel connector. I had to bring it to a place to get it smogged and the guy broke the plastic connector off for me. I had the rubber hose glued to what is basically a brass nub that the plastic thing fit on . The nub isnt long enough to attach the vacuum hose directly. So this time I epoxied a L Shaped adaptor onto the egr valve nub and attached the hose to it. I think I may have gotten the light because the hose wasnt connected very well.
The epoxy will set by tomorrow and ill see what happens., Shoots. I can remember when an EGR valve for a chevy was $15.00. Now they are double that for an aftermarket no-name valve. Since this one is only 3 years old, im trying not to spring for another one.