I have a 89 f-150 with the egr stumbing problem I took the vacume source off the egr and it stoped stumbling so what is the cure to fix this thing

Thanks in advance
Duane

 

Remove the two bolts holding it on and slip the gasket out. Use as a template on a thin piece of stainless and trace the outline. Instead of the large hole drill a small one (1/8 in). Replace with new gaskets on both sides.