Thanks for the information Drewmcg. Just some background on my 2005 Explorer with the v8 and what prompted all of this. Originally I started with overheating at idle which went from being at idle to all of the time so I checked the normal things, the hoses for cracks and the radiator for hot spots. I found nothing with these, I did find that it seemed my water pump wasn't pumping correctly so I replaced that, after putting it up on a lift at a friends, I noticed coolant leaking (more like steady trickle of coolant) coming from top of engine. I bought the kit to check for fuel fumes in the coolant lines which showed there were none. I then pulled everything apart thinking maybe I had a crack in the intake manifold that I couldn't see and sure enough there was a crack right under where the thermostat went, it was only visible from the bottom of the intake manifold plenum. I replaced this and now my vehicle won't idle without pulling the electrical connector to the MAF sensor, I replaced it since after testing with both Forscan and a multimeter the voltage it was showing was way off (under a volt) at all times.
I also pulled the pcv valve and hose since my hose didn't clip correctly and the pcv valve was absolutely caked with oil. I tried to clean it but it didn't help and since it was only a $7 part I replaced it as well as the pcv hose that didn't clip since the clip was missing. I knew my EGR valve was bad also since one of the vacuum nipples was completely broken and the other one had a crack in it so I replaced it also with a motorcraft one from Rockauto. I cleaned the throttle body with throttle body cleaner also. I then proceeded to reset the computer with a video on here, and still it will not idle with the MAF sensor plugged in. I sprayed starting fluid around the vacuum lines very liberally, this had no effect at all. With the MAF sensor unplugged it idles but extremely roughly, I also checked the conduit coming from the air filter box to make sure it wasn't clogged or anything of this nature. I'm not throwing any codes related to fuel or anything, just some for air bags being deployed which I believe came from whoever owned it before myself. I've been trying to track down anything that was off or broken and these two pieces were the last 2 things I could find that are broken or just missing. At this point I'm out of ideas, I greatly appreciate any help or suggestions to try to resolve this. I'm going to get a vacuum tester as it seems that I should have this anyways really for the future and try to test for vacuum pressure elsewhere, where would be the best place for me to do this on this vehicle?
