Like title says I got a 94 ls I just swapped a JDM type-r into. Im using the JDM ecu (obd2a) in it with a zerg jumper harness. It runs perfectly fine cracks vtec and all problem is my cel is on and im not sure how to pull codes on it and it only comes on after driving a little bit. Now I know you can jump the obd1 service connector and count the engine light blinks but im not sure if that would work on the obd2 ecu and I don't want to run the risk of frying my ecu any help would be awesome thanks!!

 

Yes you can jump the service connector and still pull codes the same way..sounds like an o2 sensor code

 

Alright cool. The only problem im facing is that the ecu isn't keeping the code in memory I turn the car off and it clears itself. Like I said before it only comes on after driving it, I had it idling for almost an hour or sowhat after I did the swap and revved it up to about 6k-ish and no cel. Kinda frustrating. Thanks for the help

 

Just jump the service connector when the CEL comes on without shutting off the car and count the blinks

 

Finally got around to pull the code. It was a 23-knock sensor. Started to ohm out the knock sensor circuit and turned out that the terminal I put in on the strut tower connector wasn't contacting the engine harness side. I ran the vtec and knock sensor wires thru the factory harness to make it more clean looking. Fixed that and no light! Drives perfect!