Is there any difference between these two ECUs, fuel map, redline, etc...I have a p75 in my LS swapped civic (B18B1) and just obtained a pr4. As far as I know the p75 is from 1994-1995 tegs and pr4 is from 1996-200?. I just wanted to know which one's better or if they're both the same.

 

They are both the same. LS non vtec ecus. what year is the car ?? id say just roll with what you have ...

 

my cars a 95 the engines out of a 94

 

Use the P75. There's no reason to put an ecu that is a different OBD than your car, you'd need to buy a conversion harness to plug the other one in anyways.