Before you take it to the stealer....uh dealer take a hammer or other suitable tool and give your EGR valve a good thunking. If it is stuck open it will run like crud at low rpm but it should run ok at higher RPM, maybe you have multiple problems.

1986 4X4, 1991 22RE, 5.71 gears,ARB Rear, aux fuel tank, 3mm O/S TB/intake, engnbldr cam, LCE header, magnaflow w/2.25 exh. custom 4 color paint job :-P 33X12.5 Goodyear MT/Rs