I have been pulling my hair out trying to figure this one out.

Symptoms:

Rough idle 9-1500k
idle speed (low throttle) sputters
Full throttle 7psi (WTF)

What I have done so far:
Checked for boost leak
Checked for any leaks
Checked spark plugs (black on the bottom, white on the top???)
Checked wires
Checked timing
Checked ECU
Checked ISC
Checked fuses underhood-on battery
Checked blocked off EGR
put datalogger on it
gave a funny O2 reading... put in another o2... gave a different reading but still ran like shit.

Put a different coil pack on it....

ARRRRRRGH! WTF.... Where is Jerry when you need him?