My check engine light keeps coming on everytime i drive my car. It will pop up anywhere from 2 to 4 minutes after i start driving. If the car sits and just idles, it will not come on. If i shut my car off and turn the key back to get the code, it wont be there. I have tried pulling the code with the car running- that did not work. I have tried putting the car in 5th and easing off the clutch to let it die so that the key would be in the on position still and the check engine remain- still no code when the connector jumped. I have no clue to what the problem is and id like to get rid of that pesky light. Anyone have any ideas as to how i can pull this code??? Also, the engine runs fine. Vtec still engauges, and i have noticed nothing unusual about how the car is driving. Another note: the started a few weeks back. At first the light would pop on at random times. It may be 30 mins after driving or longer. It started coming on more frequently. Now, its maybe 2 or 3 mins and i see it staring at me!!! Everytime i drive the car it does this.

Car: 1995 prelude SE
swapped jdm h22

Thanks in advance,
Brad

 

Bad o2 sensor usually does this, but you will feel some hesitation when light comes on during certain rpms in acceleration.

 

I will pay closer attention today and see if i notice any bit of hesitation once the light is on. Is there any way to test an O2 sensor?

 

When you jump the CEL does the light come on at all or does it remain blank?

 

If i cut the car off and jump the connector, the light remains blank. Which i always thought that the code was stored reguardless if the light was on or not. If i kill the car with the 5th gear start, the light remains on, but does not do the morse code blinking like its suppose to.

 

make sure that your actually jumping the connector. first time i did it i the paperclip i used was a little bit to big. it still fit in but it didn't fit in all the way, so it didn't display a code. smaller paper clip and it came on fine.

but, if it is the o2 sensor, the cel will kick after a constant cruising speed for a few minutes or WOT. if thats when your getting the light, you may want to test your o2 sensor

 

how do i test an o2 sensor? the light does only come on during driving condition. when the car idles, it does not come on. or at least not in the amount of time i have let it idle. (7 or 8 minutes) i am 99% sure i am getting a good connection on the jump. same piece of copper i have used times before. i will try a small paper clip just to be 100% sure.

 

i don't recall off the top of my head, but if you have the Helms manual it goes through step by step how to diagnose the whole circuit.

 

Yah,I've got the helms. I actually didn't even think about looking there. Ill do that this evening. Still! Anyone else got any ideas on how to diagnose this check engine light problem?

 

no one?

 

My suggestion would be to pull the code.

 

Take it to a parts store with a code reader; they will almost always read it for free. It's possible there is a short somewhere in the SCS line not activating the code, but it should show up on the OBD port when they scan it.

 

Since the OPs car is a 1995, it is OBDI. Parts stores only do OBDII.

 

ive seen EGR problems cause this on hondas, since the egr is inactive when the car is idling. same issue that youre having, code clears when the car shuts off. an o2 sensor problem almost always causes at least a tiny hesitation.

 

Thanks for all the input. I got my helms and I'm going to see if it has a trouble shooting guide for and 02 sensor and now the egr. I should have time this weekend to run thru it. Ill update when I find the problem incase anyone else has this issue.

 

It does.