A P28 equivalent is an ECU that is electronically identical to a P28 ECU. Most P28 ECU's use the common honda '11F0' ECU circuit board with the correct components soldered onto the board. Other common ECU's like the P05, P06, PR4, etc may also use this same circuit board but have some electrical components not soldered into place that the P28 has. Our 'p28 equivalent' adds the necessary components to another 11F0 ecu board to make it identical to a p28. The only difference is basically that we've installed the electrical components rather than the ECU manufacturer.