Can bad egr valve cause overheating?

Can a dirty or faulty EGR valve cause overheating. My 2001 PT Cruiser is overheating but only on very hot days and when the air conditioning is on. Back flushed and pressure tested the radiator, changed the thermometer, fluid was low but doesn't seem to be loosing fluid since refilled. Check engine light came on and indicated poor air flow through the EGR valve. Is it worth replacing prior to pulling the radiator to check that for the problem with overheating? Mechanic I trust doesn't think the EGR can cause overheating.