I recently swapped a b20 into my 93 civic. Check engine light wasn't on.. then I turn the car off, start it up hours later and the light is on. The car is in limp mode, setting the rev limit to 3000rpm. When I tried to pull the code the light is on solid. Its not flashing the code out. I reset ecu by pulling 7.5A back up fuse... start the car back up no check engine light on.

Once I reset ecu I can drive as much as I want, no check engine light. The minute I turn the car off and back on the CEL is on.. but I cant retrieve the codes.

ANY SUGGESTIONS? Thank you HT

 

BUMP.... Running a P75 if that matters

 

That means no codes.

 

P75 is a non vtec ecu. Not only will it throw several codes, it will also run it very lean (vtec head flows much better than LS/B20 head)

But it sounds more like you have an ECU or sensor issue. Try another ECU.

 

A solid check engine light does not mean "no codes" that means its a bad ECU.

Also, if he uses a P75 on a B20V, it wont throw any codes (assuming everything else is in good running order), it just wont engage VTEC.

 

Is that so? So your saying i have a bad ecu myself?

 

Thats always been my understanding. I could be mistaken.