Engine Rough at Part Throttle Under Load Conditions

1. EGR vacuum hoses improperly routed.
a. Check hose routing; correct as necessary.
2. Loose EGR valve.
a. Tighten valve.
3. Sticking or binding EGR valve.
a. Clean EGR valve passages.
b. Perform EGR system check.
4. Missing or incorrect EGR gasket.
a. Install new gasket and tighten valve.