If it works right an EGR when removed might not increase performance. It depends on the system. On another note if the valve goes bad it will put excessive exhaust in and causing the stumblingsurging etc that was stated and can also cause light throttle pinging. On some cars you have to fool the computer that it still works if you take it off. Had this problem with a friends Neon when he did a engine swap. He used a block off plate for the egr but left the lines connected. The computer would throw a code for EGR system. I had to decifer the service manual and interesting enough all he had to do was leave the line open to atomsphere. Last I heard he hasnt popped an EGR code again. They also came on the mid to late 70s Chryslers.:barf: