How much would a 98' jdm OBD1 ECU help my car? currently my stock ECU keeps going into check mode, when I had my compression test done the shop told me it was because the motor was such higher compression now. Is this right?
Oh.. my car has JE SRP oversized pistons, eagle H-beam rods, and a mugen headgasket, the head is stock(for now). Otherwise just basic bolt-ons, AEM CAI, 3" Apexi N1 exhast, ect.

Thank You everyone!