94 Explorer is throwing code 332, "EGR valve opening not detected." Did the following checks:

• Applied vacuum to the valve. Heard it click. Waited 60 secs, released the vacuum, and it clicked again. So, the diaphragm is not leaking.
• Ohm-checked the regulator. It was within specs.
• Removed valve, thoroughly cleaned mating surface, looked for obstructions inside. (There were none.) Re-installed with new gasket.

Anything else I should check, before I take a guess at which part to replace? What is it that actually "detects" the valve opening, anyways?

 

Does your '94 use a Differential Pressure Feedback EGR (DPFE) Sensor? If so, that is probably not detecting a change in flow when the EGR is open. Pretty common part to fail on Fords.

-Rod

 

Yes, it has the aluminum sensor with two hoses connected to the EGR pipe. I read something about checking for 5 volts at the sensor, but it didn't say which of the 3 wires are what.

 

I would suggest getting a wiring diagram (even the one in Chiltons is workable. you can access a free electronic version of Chiltons on autozone's website). The 5V reference voltage will be the lead that the DPFE shares in common with several other sensors.

 

You should also ensure that there are no restrictions in the differential nipples and the exhaust supply tube to the EGR.... Philip