2000 GTI VR6 2.8L 12 valve. I've replaced the plugs, wires, coil pack, timing chains, tensioners, rails, manifold gaskets, ALL vacuum lines, fuel psi regulator, O2 sensors, catalytic converter(magnaflow), MAF is about 2yrs old, and I've ran seafoam at high concentration in the tanks and via vacuum line in the intake multiple times. It's throwing misfire codes for cyl3&5 intermittently. The light will go out after awhile and then come back on for a while. All I can figure is a weak fuel pump or a clogging fuel rail as 3&5 are on the same bank. Compression checks out ok. It's not a dead miss either, big change when disconnecting wire by wire. Anyone have a fuel psi spec at the shrader valve? Why else could this be? Help please!?