i just did a auto to manual conversion...i got everything done...i just need to know if i need a obd2b ecu with a 99 harness....my car is a 99 civic and the motor is a 97 and it has the stock engine harness...so i was wondering if i need to change that out so it will start...because i have 4 plugs that plug into the ecu and the 97 ecu i have olny has 3 plugs...is there something im missing.....

 

you need an ecu adapter from OBD2A to OBD2B 96-98 is obd2a has 3 plugs and obd2b is 99-00 and has 4 plugs.


cheers

 

do i have to change out the inside harness???

 

u need the 99-00 ECU if your HARNESS IS 99-00

 

my engine harness is a 97....so i just need to change the harness then???

 

what do you mean inside?
under hood or in car?

 

in the car since it was automatic

 

it has 4 plugs because it was auto. One of them went to run the auto tranny. Unplug it as u dont need it anymore and do the IACV fix.

 

If its a '99 - '00 chassis you need a '99 - '00 engine harness. If its a '96 - '98 civic you need a '96 - '98 engine harness. If you try to run a '96 - '98 harness in a '99 - '00 civic or vice versa you will find that the engine harness does not plug into the underdash harness. As already stated the reason your harness has an extra plug is because its an automatic harness. I do recall Katman saying he had weird problems with not being able to get vehicles to start with automatic EX harnesses and could never figure out why, not sure if this also applies to Y7 harnesses, just kind of a heads up in case the car doesn't start.

 

I have a 97 EX witha 97 EX auto harness and a manual conversion. It works fine. The auto ECU is throwing codes but i guess thats because of no tranny? And if you plug all 4 plugs into the ECU even on manual it wont have an IACV problem. But ur still gonna have to do the fix.