So recently purchased an automatic 99 civic lx, car came with a d16y8 swap however they did not change the harness so it has the y7 harness and p2e ecu, therefore running fairly rough. My questions are so I need a new ecu? And does this new ecu have to be flashed to my car? I also replaced the dizzy, gained some power but lack of power under acceleration and bogs out. Spark plugs are good, wires are good. Codes are stating random misfires. I also bought a timing gun and adjusted timing accordingly but no luck. Any help or insight is much appreciated thanks

 

Running the p2e y7 ecu for or the y8.. find yourself a p2p ecu, wire in vtec and should be good to go. I think... pretty sure your cars harness is what you want so no need to change it.

 

I did pick up a 98 p2p but didn’t even turn the car over, someone mentioned to me it needs to be a 99 ex p2p, does that sound right?

 

Yes I believe so since the 98 is obd2a and your car is obd2b you would want to source the newer 99-00 model auto ecu. I've read about needing to wire in the knock sensor for the y8 aswell. There was also info about the iacv, an auto had the 3 wire while the manual had a 2 wire plug unless I misread some things. So hopefully your y8 was from an auto.
I'm no expert on swaps but have some insight, pretty sure you will get more knowledgeable people chiming in to help with correct info to get you going on the right track.

 

Just picked one up, and lucky for me they swapped the trans with the y8 so hopefully good there.