Been working on the truck lately and have been thanking back to when I did my plenum gasket replacement and header install. I had to delete the egr because of the headers. I found a plug that would screw into the port on the back of the intake. I reinstalled the egr valve and left the wires plugged in and the vac line on it. Thinking that would keep me from getting egr check engine light. But I know the plug I have in the intake may not be totally air tight because it was not the correct thread it only went in a few turns. What opens the egr valve? It is vac or does it have to have exhaust pressure to open?

 

Both . It's one of those awesome convoluted contraptions they came up with back in the day. The valve itself is operated by vacuum, but the valve control uses exhaust pressure to control vacuum to the valve in conjunction with the electric portion of the valve control. Basically PCM activates vacuum to valve but too little exhaust pressure bleeds off the vacuum causing the valve to stay closed until revs/exhaust pressure come up.

 

I completely “deleted” mine, and no CEL thus far.

 

I thought about doing it that way but didn’t know if it would freak out with the wires unplugged. I don’t think having the valve in place will hurt anything will it?

 

It shouldn’t. Try it, but remember how everything goes just in case it acts up. Magnum engines are unpredictable.