What's going on guys I have a 1991 civic dx hatch with the original d15b2 dpfi motor in it with a automatic transmission. I notice every time I take it for a drive and go 45-50 mph the check engine light will come on and I don't know what can this be from since the car has a lot of new parts. I would try to check the code but the thing is every time I turn the car off and turn it over to check for flashing check engine light it's gone. I'd really appreciate it if someone can help me 🙁

 

Check the light while it's running right after it's triggered.

 

Ok so just put the paper clip inside the blueish connector on the right passenger side under the floor mat and observe the flashes on the ecu while its running?

 

You shouldn't have to jump anything, just check the LED on the ECU.

 

See stuck thread at the top.

 

thanks for the help

 

Also, I think a vacuum leak