Checking the EGR Valve

The following two pages tell how to check the EGR valve operation. Found out mine wasn't even working. Could be bad solenoid or ECM or both. They also said my cold start injector may not be working either. They got pretty much everything else done, but have ordered parts for the axle and to do and check the brakes.

Basic: The EGR valve controls the level of NOx produced by the engine. If it fails to operate, it could cause a 'fail' for emissions testing. It can also cause engine combustion temps that are too high which can cause a lot of 'pinging' and 'knocking' sounds on acceleration and part throttle cruise.