Pulled a JDM D15B vtec out of my other civic, to make my CRX SI. Got to the point where the CRX starts runs and drives, Because it is not stock OBD 1 I cant figure out how to get the check engine codes.

Current ECU: P07 with a wire harness jumper for OBD0 to OBD1

Car is Currently running in safe mode with RPMS limiting at 3500, really my only concern.

 

No clue why you have a P07.

The D15B should be run on a chipped P28 (or similar OBD1 VTEC ECU) with a D15B basemap already installed.

Your concern should be that you are trying to run a motor on a computer that isn't remotely designed for it.

Well, I don't even know what D15B you are running so who knows. Is it the VTEC-E or whatever? I was thinking of the Z6-ish equivalent.

 

Picked up the P28 and got it chipped also picked up a monotech wire harness, All i have been told is its a JDM d15b Vtec. only problem that I have now is the plug for the wiring coming out of the firewall on the driver side is rectangle, and for the Monotech harness in round

 

...I don't know that you needed a monotech wire harness. I would have just bought a cheap OBD0 to OBD1 wire harness of ebay ($40) to plug into the ECU and into the car's ECU harness.

I can't help you with this harness.