Hi, i was hoping that someone could help me, i had the valve cover gasket repalced, The car hesitates at acceleration, when i give it gas around 60-80 it will start chocking and the gas pedal will viberate. The coils and spark plugs were inspected and the machanic said they were fine but im still getting the same hesitation and stalling so i tryed pennzoil fuel injection cleaner and it didnt work, tryed pennzoil full system cleaner still didnt work and lastly pennzoil octane booster. what should i do? Thanks in advance.