My 95 F150 with the 5.0 and 4WD has been throwing the 332 code, "Insufficient EGR Flow" code for a year now, and I have traced the problem back to the EGR solenoid, after testing the valve by applying a vacuum (sucking) on the vacuum fitting and getting engine stumbling, testing the juice can vacuum reservoir for leaks, finding a strong vacuum at the lower, black hose connection at the solenoid, and seeing no vacuum at the green nylon hose that goes to the valve. I pulled the electrical connector off of the solenoid, and found battery volatage, about 13.8V, across the plug. The voltage did not change at idle or while revving the engine at about 2000 RPM. Does anyone here know if this is normal? I'm about to go buy a new solenoid, but want to check if anyone has had this problem and has fixed it.

 

It is normal. Power on both sides says that the coil is good in the solenoid.
The computer does not ground the solenoid until the engine is warmed up and the truck is at mid throttle on the road.
Some say they have seen the solenoid open with a warm engine at mid throttle with the truck standing still but I can not say it is so.

 

There is no 332 code for KOEO so I will guess you are getting it from CM.
If you got from KOER then the below will not apply.
Let us know were the code came from, it makes a big difference sometimes.

Continuous Memory (CM) DTC 332 indicates the EGR valve did not open with the engine stabilized and the EVR solenoid duty cycle present sometime during vehicle operation.

Possible causes:
-- Obstructed or cracked hose to EGR valve.
-- Icing.
-- Damaged EGR valve.
-- Damaged EVR solenoid harness.

 

Another simple test of the system, use a jumper wire to ground the brown pink wire at the EVR, the engine should stumble.

Same thing the computer would do once at cruise speed, if engine stumbles shows both EVR and vacuum aspects of the system are good pointing to the EVP as the problem.
Or the computer simply isn't commanding the valve to open (not likely) or a problem in the circuit between the computer and the EVR.

 

The 332 code was from the continuous memory, and has come up after the first time the engine revs for a few seconds. I understand that the 13.8V across the plug shows that the ECU is working properly, and I will check to see if the valve opens when I ground the brown/pink wire. That would verify that the valve is operating. If the valve doesn't open, I will replace the EVR, about $35 here in Tucson. Thanks and I will let you know the final story.

 

Not true.
The 13.8V on both wires at the plug only means that the there is power to the EVR and its coil is good and the wire from the EVR to the computer is not shorted to ground.
At this point it does not say the "ECU is working properly", it only says for the ECU that it is not grounding the control wire to the EVR at this point in time.
In other words it says the driver transistor in the ECU is not shorted or the ECU is not telling the EVR to open the EGR valve.

 

OK, I fixed it! I was going to buy a new EGR solenoid valve (EVR), but when I compared the new to old, all the suspicious operations were the same! The resistance across the coil was about 4.8 Ohms, and air could be both drawn and blown through both tubing connectors. I thought that would leave an open vacuum connector in the system, but I guess there is something I don't realize. Anyway, I supplied battery voltage to the plug, connected the tubes, and grounded the brown/pink wire, and the engine stumbled. I reconnected everything properly and the CEL no longer comes on! It has been more than a month now, and I really don't know what it was that I fixed, but I noticed that when I first applied suction to the EGR valve, there was a "pop", so maybe the combination of unsticking the EGR valve and messing with the vacuum tubing fixed the system. Moral: don't buy a new valve until you check out everything else... Thanks to danr1 and subford - couldn't have done it without you.