Purchased a 1999 Honda civic lx, previous owner swapped the motor/trans to a d16y8, car has been running rough and misfiring. Recently purchased a 1999 Honda civic EX ecu, went to plug in and car starts over but sputters a bit and then dies periodically. Replaced the distributor with a brand new one, new wires, new spark plugs too. The car still has a y7 harness so vtech and knock sensor are not hooked up. Not too sure if that would cause the problems but I didn’t think so because as far as I know vtech only kicks in around 3-4k RPMS? The d16y8 has the original auto trans it came with too, no other modifications and at a loss of what to do without spending anymore money on guessing. ANY help is appreciated thanks

 

Check the ECU to see which one it is.

 

It’s an obd2b from the same year ex Honda civic which is what the motor is out of

 

Then you need to wire up all the additional sensors for the ECU to operate normally.