What would best ecu for my 99 si that's swapped with a jdm gsr?

 

99 GSR.

 

oh yea forgot to list mods intake header exhaust and skunk2 intake mani

 

No kidding.

 

I like this man ^ u want a JDM obd2b p72 ecu

 

Unfortunately, a '99 GSR ECU is still an OBD-2A plugged ECU... which doesn't plug directly in to the EM1 chassis/engine harness. You would have to get a '00-01 GSR ECU to plug it in directly, however, it won't start because the '00-01 GSR ECU has an immobilizer circuit.

Grumblemarc was right... but you will need an OBD-2B to OBD-2A harness adapter to plug that '99 GSR ECU in.

Good luck.

 

Something else he conveniently forgot to tell you. He's "going turbo". Check his other thread asking this same question.

 

I didn't think think the JDM obd2b had Imm