It can be wired for either with an external jumper, BUT for P+H, It fires ONLY ONE injector.. A 730 can't handle a 100% overload for injectors in Saturated, (Ismoked one trying to fire 16), So I would guess the same thing for the P+H. The 749 will fire 4 P+H Grumpy > Group. Does the GM 7730 ecm use P&H or High Impedance Injectors??? > Inquiring minds want to know... Sharpe