I took my 96 Ranger auto 3.0v6 out for drive last night trying to see about another problem and discovered the SES light on. My wife informed me that it has been on for a while. When I hooked the reader up to it a P0401 code came up EGR low flow what ever. I've have had previous experience with this on my 150 and after replacing the EGR valve, still had a SES light & code. I then replaced the EGR solinoid, light stayed off. Is there a way to find out which part is bad with replacing both parts and wasting a whole weekend.

 

The most common cause is the DPFE sensor if the 96s had them, it's located on the front of my intake manifold.

 

Autozone will have your wiring diagram for you to track it down, as will a Haynes manual if you have one on hand. DPFEs are well known for faulting and popping EGR codes.

 

I's also be thinking the DPFE sensor. Here's a quick Summary of the Ford DPFE/EGR system.

 

Just to add my two cents, it is possible for the passages in the intake to get plugged on a lot of engines, and the tube from the exhaust to the EGR valve to get plugged on some others. If you haven't, I'd check that you have open passages, as the code is for low flow, meaning the EGR position sensor said " I'm here", and the flow was not what was expected.
You should also be able to read a plumbing diagram for any engine 'accesories' that affect Emissions control somewhere under the hood, i.e. on the radiator support or the bottom of the hood. It should show routing for any vacuum operated thingies that affect emissions, such as, in some cases, EGR valves and PCV valves.
tom

 

I'll throw in here. The Check Engine light came on Friday morning just as I was getting off the freeway going to work. When my mechanic opened I called him and he had time to check it out. The handheld computer he has said "EGR airflow restricted..." Not knowing if it was the valve or the sensor, we replaced the valve. The light went out and we drove over to Tukwila from Spokane Friday. I drove a few miles while over there with no light. Monday, I fill up and as I'm pulling out of the station, Check Engine light comes on again. Now I have to drive all the way home with the light on, around 287 miles or so. I'm taking it in to him this morning again. I'm hoping the valve failed, but I'm also having him check the other things mentioned in this thread. Could save me alot of coin and time, frustration and heartburn. Thanks guys!!!

 

The check engine light went off today. When I stopped I turned the truck off, and turned the key back on to make sure the light didn't burn out. So far so good. Any ideas why this would happen. This is in addition to my previous post above.

 

Pull the code; it should be stored for something like 50 drive cycles.

 

I'll go by the mechanic today. I got a feeling it's going to read "EGR valve flow restricted" like it did originally. Can't hurt though. I'm thinking about getting a new DPFE (something like that) valve. Gus Johnson has them for $ 93.92. I figure it's a good investment because as the thread indicated, this is the usual cause for EGR problems. Thanks for your reponse Billy.

 

Yep, as I suspected. The mechanic hooked up his little hand held jobby and the screen read "EGR valve flow restricted". I'm just going to drive it for a while and see if the light comes on again. I'll replace the DPFE sensor (which is what I meant to say above) soon.