Note On Intermittents
With engine idling, manipulate EGR solenoid connector and related wiring. Listen for a change in idle quality. Drive vehicle with throttle angle at 8-15 degrees, and engine at 1450-1650 RPM to try and duplicate code. Remove EGR valve and check for excessive carbon buildup that would restrict EGR flow, or foreign materials holding EGR valve open. Check for pinched, cut, kinked, misrouted or blocked vacuum passages and/or vacuum hoses, reducing EGR flow. Check for EGR valve binding in up or down position.