2.5L ('98-'01) EGR Question

[Kojack]

My 2000 2.5 has been tripping a P402 code (excessive EGR flow) for a while. I just decided to check into it and found out that the EGR valve diaphragm is bad, and it doesn't seem to get any vacuum anyway, so the valve doesn't open. I was able to supply enough vacuum to partially open the valve so I'm sure its normally closed. Is there something else that can cause this code?

 

[franklin2]

Do you know what type of EGR system your engine uses? The larger trucks used a EGR valve that had a position sensor on the valve. When the computer told the vacuum solenoid to open and apply vacuum to the EGR, the computer would then quickly look at the position sensor to verify the EGR actually moved.

The other system they used was a pressure sensor system and the pressure sensor likes to go bad all the time. They have the EGR valve and the vacuum solenoid like the other system. But instead of a physical position sensor on the EGR valve, they use a pressure sensor mounted in the pipe feeding exhaust to the EGR. With the EGR closed, the pressure in the pipe is high, from the cat convertor and other restrictions in the exhaust. When the EGR opens, the pressure drops in this exhaust feed pipe. The computer sees this and verifies the EGR did open and can determine how much to open the EGR for a certain amount of flow. This pressure sensor can possibly cause some error codes if it goes bad. The exhaust gas hitting the sensor doesn't let it last very long.

 

[Kojack]

It's the pressure sensor type. I plugged the vacuum line to the EGR valve to eliminate any chance that it's opening but I still have drivability issues. The search goes on.

 

[scotts90ranger]

I haven't done too much with the EGR system but I do have 3 rigs with this style EGR with the EGPV or whatever...

If it is sensing too much flow it could be a carboned up EGR valve that isn't seating... for "testing purposes" you could back off the two bolts holding the EGR valve to the intake manifold a couple turns, cut up a drink can with scissors and make a piece as wide as the gap between the two bolts and long enough to slide between the valve and gasket with the space you made then tighten again and test...

 

[redcloud]

In my situation, when that codes come I replace the EGR sensor with an original ford sensor. I try generic but it doesn't work. Hope this work for you. I used the part of a Ford Expedition 2003. Just make sure is a FoMoCo Part.