So i know how to test the EGR valve and it is working just fine. I'm not getting any vac between the EGR Vaccuum Solenoid when warm and middle throttle. How do i determine if its the solenoid or the temp switch and how do i test each? Thanks,

 

Temp switch test. Follow the picture to see if the switch is working. You want to wire in series. This test will veriefy if the little filament type metal bends with heat, causing it to ground itself. The proper term is a "continuety test." If you wire it up to the multimeter and automatically it presents a continuety load or grounding, then the switch is bad. It only grounds itself with heat. Then your next culprit would be the solenoid. I dont know how to test this one but if you suspect it is bad, you should change it out because it is directly connected to your ECM. According to the ECM sticker, it warns that if any solenoid is under 20 OHMS, it would damage the ECM.