obd2 harness

I need to fingure out if my whole harness is obd1 or if they used a jumper to switch it from obd2 to obd1. The car has a p28 ecu(obd1) in it and i want it to be obd2 but i need to know if i need a whole harness or just frome the firewall back(and i have looked under the hood and along the ecu wires but because it uses an obd2 dizzy injectors and all that crap that mabey the harness was cut some where and i need to know what to look for, like plugs that are diffrent between obd1 and obd2 . Oh and how big of a pain in the ass is it to change the whole harness over cause im trying to refferee my car.

look at the ecu plugs, you would know if they used a jumper

so it would be at the coneectors for the ecu not the fire wall

This is what happens when you don't give out enough information, you get answers that don't fit the "question". You should have stated that you have a '92 Civic (OBD1) with an OBD2 engine. For all any of us know, you could have a '99 Integra Type R. This is stuff you need to explain when asking for help. Just to let you know for future reference.

The only thing you can do is to check to see if the wires were cut on the engine harness side of things. Your car ('92 Civic, as stated in your profile) has the ECU connectors for OBD1. The OBD2 connectors on the engine harness will fit into the OBD1 connectors at the shocktower (the connectors leading to the ECU through the firewall). So basically you need to check the wires going to the alternator, distributor, and injectors; to see if they were modified to plug into the OBD2 parts. If they weren't modified, then you have an OBD2 engine harness. If they were modified, then it's an OBD1 engine harness that was wired up to work with your OBD2 engine.

But... you should only have to get the OBD2 ECU and an OBD1 to OBD2x conversion harness (x = a or b depending on the year ['96-'98 is OBD2a and '99+ is OBD2b]). Since you already have the engine all properly wired on the engine harness side of thing (whether it's the OBD2 or modified OBD1), you only have to worry about getting the right ECU pluged to it.

thanks i'll look and sorry for the lack of info cause i know that is the most improtant part