i have p 28 ecu, i opened it up and it doesn't seem to be chipped. what i want to know is will run a stock ls engine. cause i just bought an eg hatch w/ ls swap it had broke a rod so engine is no good but i have a spare b18b engine so its no big deal. i was in the middle of putting the engine in today and started to wonder what computer it had in it, i was expecting to see a p75 but it has a p28. and like i said it doesn't seem to be chipped. so will the p28 run my ls set up or should i buy a p75

 

with the right chip a P28 will run the B18B fine.

IMO, sell the P28, buy a P75 and have money left over.
(a chipped P06 would work as well.)

but if you plan to boost a chipped ECU would be the best move.
If you plan to drop on a VTEC head in the future stick with the P28 and have it chipped.