Yah, part throttle/low load conditions are when EGR comes into play, that's why the SES light comes on. If I were you, I'd change the EGR and solenoid, since you're gonna be back there anyway. Hopefully you can reach it without too much trouble. When I did mine on my Impala, I had plenty of room, but the EGR is under the windshield in your Camaro.
Might be a bit of a pain to get the gasket and bolts out.