can a pr4 ecu be chipped with a pr3 chip? or are they completly different aside from vtec and knock sensor wires and all ...checkin for a distant friend with ls vtec

 

non-obd (90-1) cannot be made into vtec without the aid of Zdyne or other completly rewritten honda code.

92-3 PR4 can be made into vtec ecu, as the boards are compatiable with the P28/P30/P61/Pr3-J01 and few others

 

thanx man thats exactly the info i was lookin for