EGR PO402

I have a 1996 Ford Explorer V8 5.0 AWD and the check engine light was on and it said the following.
P0401 EGR Flow Insufficient Detected
P0402 EGR Flow Excessive Detected

I first took the EGR off and cleaned all the carbon out. It was stopped completly up. I cleared the computer and drove it and light came back on. Then I got this code.

P0402 EGR Flow Excessive Detected

First thing I replaced then was the EGR Valve Position Sensor on the EGR. Reset computer drove it came back up. So I took that off and put my old one back and replaced the EVR because the 96 explorer with 5.0 said it doesnt have the DPF sensor. The EVR is like the DPF and it came up with same error after replacing that. So now its back to the EGR. The EGR seems to work fine. The truck runs like a dream no miss what so ever but i cant get the check engine light to go off. everytime i reset it comes back.

P0402 EGR Flow Excessive Detected

I unhooked the vacuum line on the EGR itself and when i apply vacuum to the EGR opening it up the engine dies down and almost stalls then when i release the vacuum it returns to normal idle. What could this be?