He can try electrically disconnecting the Exhaust Back Pressure Valve (EBPV) by disconnecting the two-wire weatherpack connector at the base turbo, driver's side. See if that helps. Also check to make sure all hoses/connections from the turbo to intakes are tight. Check the hose from the passenger side intake to the MAP sensor located on the firewall, just to the passenger side of center. He can try electrically disonnecting the MAP sensor and see if running in "default mode" hepls. It will set a Check Engine Light, but if it's better he needs a new MAP. Just a few things to get him started! Cheers!
