I just put on some new MSD plug wires since the originals had 85K miles on them and I put some washers behind the ICM to help keep it cool. But I got the flashing SES light before it came on and stayed on. It will go out in a day or two and then come back again. The car (96 Camaro SS) actually runs great and you can't even tell anything is wrong when the light starts blinking. Could it be a leaky injector dumping too much fuel and causing the random miss? Could it be something to do with the crank position sensor? What have you guys found that solved the problem? I can't pass inspection in NJ with the SES light on.

 

Get it scanned at your local Autozone for free, then tell us what the code is and we'll go from there. There are hundreds of possibilities...

If the light is blinking repeatedly, then it's a misfire @ a specific cylinder(s)

 

You need to get the code pulled. In the meantime, check all plug wires to be sure they are secure, and not grounding or barely attached.

 

OK, got the car scanned this morning and it came up with code P0300 Random Misfire multiple cylinders. It comes and goes and the SES light will blink when it comes back. The car runs awesome and you can't even tell there is anything wrong when the SES light blinks and the code comes back. Does the crank position sensor have anything to do with reporting misfires? I don't think there are any signs of the opti starting to go bad. The car has 85K miles and I just bought it so I don't know any history of previous repairs. Looking for suggestions of where to start. I did the washer mod to the ICM but that didn't seem to fix it.

 

Yes the CKP is what is used to determine misfires. Assuming you don't have a code for the CKP it should still be looked at for any type of contamination that could cause it to act faulty.

EGR faults and random misfires are difficult to track down. You could begin to look at the plug wires. You know, view them from all angles in the dark, check for burned spots etc. Also see if you get the misfire counts at idle or just under load. If at idle, you could use an inductive timing light to see if the misfires are detectable that way.

On another note. That's interesting you are from Ewing. I got my degree from Trenton State College. and my 94 is Hugger orange.

 

Jeff, just put a piece of duct tape over the SES light...

Blinking SES is misfires. My blinking SES turned out to be #6 and #8 Taylor OTVC wires had bad crimps at the OPTI. I used a meter to find and resolve.

 

The P0300 can be maddening to track down. Could be a fouled plug, bad wire, loose wire, etc. Just do a search and see how many threads there have been about the P0300, and there is not a consensus answer.

 

Well, it looks like I figured out the problem. Since the car is running great I guessed it wasn't ignition related but rather a lean out condition. Then I noticed the light come on when it seemed like the car was going into EVAP purge mode. So I checked the pruge line from the intake manifold back and there was way too much airflow with no real restriction. So I climbed under the car and found 2 of the rubber hoses were rock hard and the plastic purge line pulled right out. I also removed the charcoal canister and you can hear stuff moving around in it so I replaced that. I put new rubber hose on the purge lines and the new canister and I rechecked the line at the intake and there was now a very limited amount of air coming through along with lots of bits of charcoal! So it looks like the purge line being loose and leaking and the canister being shot allowed too much air back into the engine which leaned it out causing a very hot combustion chamber or exhaust that could damage the cats triggering the P0300 code. What I don't understand is that there are purge flow codes and they did not get triggered. Oh well, it seems find now and I should be able to pass inspection now. Good luck to others with the P0300 code.