Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
The EGR valve on your model is an electronically controlled design; the powertrain control module pulses ground on and off to cause the EGR pintle to open the amount desired.
This type of valve can still be cleaned, if you hapeens to find a chunk of carbon deposit holding the pintle off of it's seat. This would be rather unusual though; the usual failure with this design is a poor internal electrical connection that requires that the valve be replaced.
You can test this valve but a professional level scan tool is required to do so; this type of scan tool can be used to command the valve to open and close in calibrated increments while monitoring it's response (as read through tvalve's internal position sensor) on the scan tool screen.