2005 won't accelerate

I have replaced head gasket, plugs , wires and catalytic converter and under load or in Park when you give it gas it losses power

what is your fuel pressure? have you scanned for codes? what are your fuel trims looking like? What are your o2 sensors showing? Injector pulse width?

Same exact problem i have. you figured it out?? Could it be a vacume leak clogged fuel filter injectors plugged i dont get it just can not figure it out