Sub-EGR Valve
Operate sub EGR valve manually. Valve should move smoothly through full range of motion. If operation is difficult, remove and inspect for deposits. Before removing a sub EGR valve that is difficult to operate, spray with solvent from the outside with rubber boot removed, then remove valve. If necessary, clean valve with solvent. Apply a light coat of oil. If operation remains difficult after cleaning, replace sub EGR valve.