Hello,

I have a 1992 Honda Accord Ex where the CEL only comes on when driving. Takes about 1-2 mins before it comes on. What's strange is when I start the car and let it idle (sometimes up to 20 mins or more) the light doesn't come on. Any ideas on why this happens? Also, the car needs to be inspected and I was wondering do they let the car idle during the inspection or accelerate the engine?

Thanks,
Troy

 

CEL turning on means engine computer detected a problem. To find out what the computer detected, read the code(s). I wrote a thread called how to get CEL codes in the main DIY section that will tell you how to do this.

 

I was able to get the code using PAhonda's method. The code is a code "12" which appears to deal with the EGR system. Any ideas on this would be most helpful.

 

Based on the 95 procedure, you should pull the 7.5 amp backup/radio fuse to reset the ECU. See if the code returns. Make sure that you have the radio code.

Next, you should pull the vacuum line off of the EGR valve and feel if there is suction when the engine is idling. The EGR is number 18 in the pic below. There should be no vacuum on it when the car is at idle.

 

Thanks for the quick response. I will give it a shot later.

 

I reset the ECU and I the CEL came back on, but this time it took longer. It usually comes on after about 2 mins. of driving, but this time it took about 10 mins. I will try to see if there is any vacuum from the EGR.

 

Pulled the number 16 hose off and there is no vacuum. Any other ideas? Should I try removing and cleaning?

 

If you have some rev up the engine when the car is warm, that hose should pull a vacuum. If not, I would check the vacuum hoses on the EGR system. There should be a routing diagram under the hood, so you can trace and inspect the hoses.

If you have one of those hand held vacuum pumps, see if the EGR valve will hold a vacuum.