If you leave the valve on there and hooked up with the connector attached to the solenoid, you should be fine. Some people get away with ditching it all together and CLAIMING the light doesn't come on at all and that they DON'T have any problems with part throttle detonation but I wasn't so lucky until I had it tuned to shut off the EGR function. Remember, the ONLY benefit of ditching EGR is getting rid of ugliness or that you got a deal on some fox headers and don't have the port. EGR is NOT operating during Wide Open Throttle! There are more than a few ways to "trick" the system though.
ONE is detach the valve assembly from the intake, remove the soloenoid assy from the valve, and figure out a way to "fix" the plunger halfway down. Once you secured it like that, tuck it out of sight! Either fabricate a block off plate yourself OR you can use a 351 fuel pump block off plate.
Second is use the SAME method to block off the intake and this time...use resistors in the connector of the EGR valve to "trick the system." Here is the diagram. This worked for me but only for a little bit.
The BEST solution is Block of the intake...and get the car tuned to actually SHUT OFF the EGR function in the ECU.
Make SURE you take all associated vaccum lines and CAP or PLUG them. This is most important on the intake manifold to avoid leaks. Tuck any lines out of sight. If you have your car tuned to eliminate EGR, you can safely remove the emissions stuff in the fenderwell on the passenger side as well...just leave the Charcoal Canister in tact.
Again, some people get by with out idle surge, check engine lights, or part throttle pinging. If you do, more power to ya! But my car wasn't so lucky.
There you have it! The ins and outs of EGR delete!