ok if i drive for more than 20 mins me check engine light usually comes on. odd thing is when its on i run better. more throttle response. no pulsing idle from 750rpm to 1000rpm and goes 55 at lower rpms (2000rpm max) usually around 1500 rpm for 55 when the light is off

but when i shut it off an start it back up the light wont come back on all day

 

your best bet is to get the computer scanned

 

Mine did this when the EGR valve went bad. Car ran great but SES light would come on after about 15 minutes of driving and then just go off. At idle get your finger under the EGR and gently press up on the diaphragm. The engine should stumble and eventually stall as you get to the end of the diaphagm's travel. If the motor continues to run ok the EGR is bad or the passages could be clogged. As stated above...get the computer scanned and see what code it spits to be sure.

 

um all those small lines from the headers...did they run into the egr system? including the one line after the cat...if so those were all removed and all holes filled with threaded plugs

if not then ill pull the egr valve clean it check for clogs ect ect but thats if it dont sputter when i open the egr

i only get code 12
diagnostic mode

odd huh

 

Those were part of your A.I.R. emissions stuff, not EGR. The air pump injected air into the exhaust manifolds and into the cat as part of the engine emissions. There wasn't a post-cat air line, or any post-cat diagnostic (oxy sensor). And taking all that stuff off DOES NOT affect your engine nor will it make your engine light go on. All that stuff "fell off" of my 91 as well. Your engine is fine without it. But I can't speak for your EGR, so I would check it out as suggested.

 

Camaro 69 is absolutely correct. Those plugs were part of your A.I.R. The EGR is a pretty good sized valve located on your intake manifold on the passenger side next to your throttle body. Should have one vacuum line connection on top. The valve is probably shot considering the year of your car. I seriously doubt the passages are clogged due to the fact that it isn't "that" old. Code 12 indicates your diagnostic terminal is grounded. Shot no other code....huh?

 

That EGR Test is useless if you have engine heads like mine, some 305 have engine heads with NO EGR ports at all in the head! Id say unhook the batt for a few hours then hook it back up and go for a 30 min drive, if it comes back on find a paper click and pull the codes

 

I had a 93 geo metro of which they were completely clogged.

i have yet to check. its been too cold here to want to get out and do anything

 

Well, good luck. Hope it helps. I base all my input on this site from my experiences with a totally stock 305. It is easy to hack and tear but much more of a challenge to keep a 16 year old car completely factory. This has become my new hobby...I want to own this car and have it FACTORY stock for the rest of days. The problem you described was what was going on with mine...passages were really clean though. Just a shot EGR.