I have a 97 civix dx with a full 99 y8 swap a couple owners before me did the swap its got new dizzy he says he swapped the harness from obd2b to obd2a its got z6 tranny from a 92-95 my ussues or questions are what ecu should i use it has the p28 in it now but in my state it needs to pass emmissions it is a manual trans but im new to the honda game should i get thw stock dx ecu and use a vafc2 or the stpck 96-98 ex ecu as he swapped wiring so it was pluplug and play in dash

 

You need a 96-98 Civic OBD2a P2P ECU for a manual transmission.

 

Is it a vehicle specific p2p or just any cus thats where im having troubkes figurifiguring out which one i need as ive never dealt w vtec oror honda before

 

To run the OBD1 P28 ECU, an OBD2a-ODD1 conversion harness is likely installed in your car. Remove the P28 ECU and the conversion harness, and you are left with OBD2a ECU connectors that plug into the OBD2a P2P ECU you will need.

 

Alright so this is where im at now i have gotten ahold of a p2p-a34 ecu i can plug it in and get my car to crank but wont turn over i can plug the obd2 to obd1 harness and p28 back in and fire up normal will i need to flash the ecu i was told it would just be a plug and play process w the ecu or am i missing something here

 

You're obviously missing something. No, you don't need to "flash" the ECU. You can't.

With the CORRECT ECU (the P2P) plugged in, is the CEL on? Does it work?

 

Post a picture of the ECU portion where the connectors plug in

 

 

Cel and battery light stay on when key is turned to second position

 

Can you hear the fuel pump priming when you first turn the key on?

 

Ill check tomorrow for the fuel pump if i finally got ahold of the person who did the swap he originally told me he set the car up for obd2a and now he told me it is definitely obd2b the p2p ecu i just got is for obd2a will a obd2a ecu plug into obd2b harness at all

 

Yes, perfectly.

But car won't start due to different pinning of OBD2a/2b ECUs.

 

I also read that obd2a uses plugs A, C, D inthe ecu and obd2b uses A, B, C plugs in the ecu notsure how they would be interchangable if this is right because the plugs Band D arent even same size but then again im new to this stuff ive never had to deal with. The on board diagnostics on any of my other vehicles

 

OBD2a/2b use the same ECU connectors but the pin outs differ. Do you understand the difference? And some OBD2b ECUs do use the D connector.

 

Ok i understand! ill find someone w an obd2b ecu and see if that solves my problem

 

You have a '97. You need an OBD2A ECU.

 

That's what I was getting at asking for a picture of your OBD2 ECU where the connectors plug in, I was guessing you got an OBD2B P2P and you need an OBD2A P2P

 

I have obd2a ecu

 

 

Is it an obd2a p2p ecu? If it is remove all plugs from the red retangle conversion harness and plug it into your obd2a ecu.

 

I did i also plugged the obd2 to obd1(red harness) back in and drove the car to autozone and they couldnt get the obd2a to read on the scanner (when i got to autozone i unplugged the red harness and p28 and plugged the obd2a in and turned the key to the second position and it couldnt conn3ct)

 

This is why i thought obd2a wont plug into obd2b harness and vise versa

 

It will plug in, it just won't start your car or could probably fry the ecu.

 

Its a 99 swap which i know is obd2b i was just going off what the kid initially told me about using obd2a but he never actually ran the car w the obd2 ecu just the p28 after he did the swap so im thinking find a obd2b p2p and try rhat just sucks i just spent 60 bucks on the obd2a p2p

 

Let me go ahead and clear this up.

You have a 99-00 engine
You're using an obd2a engine harness
Therefore you need an obd2a ecu
Not to mention your car is an obd2a type deal.