Hi guys,if I've had egr system deleted , do I have to remove egr valve and block off port to intake,the reason I'm asking I have a severe stumble and stalling at highway speeds ,opti replaced ,any suggestions Thanks

 

Check your fuel pressure.

 

The EGR will affect your engine's performance only if it is leaking. Blocking off the riser tube from the #8 primary to the back of the manifold will insure no exhaust gas can leak into the intake manifold. In the remote case that the EGR pintle seal is leaking air into the manifold, removing the EGR valve and blocking off the hole in the manifold would eliminate that possibility.