1998 GMC Jimmy Misfire cylinder 1

My truck runs rough and emission engine code P0301 indicates a misfire in cylinder 1. ERG valve is cleaned and PVC valve is good. Mass Air sensor was replaced about 5,000 miles ago. Oxygen sensors were replaced recently. The fuel pump sending module, fuel filter, tank, filler neck and fuel lines all were replaced. The distributor cap, rotor, spark plug wires, plugs appear to be good with 25,000 miles on them. Stepping on the accelerator does not smooth out engine, has a lack of power. Fuel pressure regulator is new. Plenum gasket and throttle body gaskets are new. Throttle body and idle solenoid are is clean. Cylinder Compression was 170 psi on cylinder 1 and 5 and psi on cylinder 4 and 6. Didn't remove plugs on 2 and 3 because they were difficult to get at.
What do you think the problem is?