So I got a 2001 GSR and Im putting in an OBD1 LSVTEC engine. I did alot of reading and searching and well I found out that I can re use both OBD1 engine harness (already wired for Bseries VTEC) and OBD2 Integra chassis harness because they plug into each other. So here's my issue. The OBD1 engine harness has 3 grey connectors and the OBD2 chassis harness has 4 grey connectors. The odd connector has 3 wires. What are these wires for and do I need to connect them or are they extra OBD2 sensors that I dont need.

I do have an OBD 2b to OBD1 ECU conversion harness and Im running a P28. Im almost ready to start it up.

 

contact the company you bought the ecu harness from and see if they have a break down on the harness layout. if not then you might want to reconsider using their harness at all. most electronic companys use a program called mitchells for their wiring diagrams and if they have it they will probably send it to you for free. when it comes to electical stuff allways better safe than sorry.

 

The ECU harness is not the issue, I was just stating what parts I was using. My question is about where the engine harness and chassis harness connect to on the shock tower. There are 3 connectors on the OBD 1 engine harness and 4 connectors on the OBD 2 chassis harness. The odd connector has 3 wires, which is on the OBD 2 chassis harness. What are these wires for?

 

crankshaft sensor i think. obd 1 cars dont have one (i could be wrong) so if your using your 2001 harness on you obd1 motor you will have an extra plug. if so its just an extra plug that goes to nothing. you also should have an extra plug for the obd2 knock sensor. your obd 1 ls shouldnt have one. if i have posted wrong info please correct me so i can edit my post. thanks.