1997 Expedition P0401 code

did you use a ford brand dpfe?

yes, I bought the dpfe and the vacuum regulator at the ford dealership. I did buy the egr valve at the parts store though. The engine seems to be running just fine, but the light comes back on after only driving a few miles when I clear it. Are there any other sensors that might cause this code?

what's the voltages to the dpfe like and if possible get a scanner reading of the dpfe voltages

I'm a shade tree mechanic, so don't have the equipment to check voltage or scan the dpfe. I 've been having the parts store scan it and reset it for me. Maybe this weekend I will pick up a multimeter. Any suggestions on the best type to buy? Is the obdII scanner you can buy a the part store capable of scanning the dpfe?

best brand of DVOM is probably a Fluke but it's not necessary to buy the best for what you'll be using it for, doubtful a code reader will give you a voltage reading of the dpfe that you require but backprobing the dpfe with the dvom might give you the results you're seeking w/o resortting to a FORD scanner

Thanks, I'll pick up the meter this weekend and keep you posted on the results.

Picked up the dvom this weekend and when I back stabbed the the dpfe harness at the reference terminal with the engine not running and the key in the on position the voltage reading I got was 5.04v. When I started the engine and it was still cold I got at a reading from the signal terminal of 1.06v., after letting the engine run for 15-20 minutes to warm up it did not change much at most it went up to 1.08v. The repair manual says it should rise up to 4-6volts. I am assuming that ford sold me a defective dpfe, or I did not clear the egr tube between the exhaust manifold and the egr valve sufficiently. Have you ever recieved a new dpfe from the dealer that was defective? Any suggestions? By the way, I also checked the resistance on the vacuum regulator and got a reading of 35.05 omhs which the repair manual tells me that it is ok. What is your opinion? Thanks for your help!

apply vaccum to the egr vacuum line till the engine stalls and watch the dpfe readings!

Should I apply vacuum to the egr valve? What should I be looking for? Again. thanks for your help!

You should be applying vaccum with a VACCUM PUMP! to the egr valve as the engine is running! The engine should stall out if the valve and the ports are clear and working. As you're doing this your voltage on your DVOM at the backprobed dpfe sensor should change. Your manual should tell how to do this! If It's not working for you then I'd suggest either a better scan tool, Some help from a mecahnic and maybe recheck the install of the egr valve.

Well Jeff I think I fixed it. Engine did not stall when I applied vacuum to the egr valve so I took the egr tube off again and soaked it in parts cleaner, ran some wire through it, flushed it, blew it out and reinstalled it. Had the code cleared and went on a 75 mile trip and the light did not come back on. It must of had some tough deposits in the orifice in the tube and did not let the dpfe do it's job. From talking to some mechanic friends this code is very difficult to figure out. Thanks for all your help, I appreciate it.

pretty common scenario on Fords unfortunately! cheers Jeff

rob wrote: Well Jeff I think I fixed it. Engine did not stall when I applied vacuum to the egr valve so I took the egr tube off again and soaked it in parts cleaner, ran some wire through it, flushed it, blew it out and reinstalled it. Had the code cleared and went on a 75 mile trip and the light did not come back on. It must of had some tough deposits in the orifice in the tube and did not let the dpfe do it's job. From talking to some mechanic friends this code is very difficult to figure out. Thanks for all your help, I appreciate it. What kind of part cleaner should be used in this case? What did you use?

brake and parts cleaner or throttle body or carb cleaner!

jeff compton wrote: brake and parts cleaner or throttle body or carb cleaner! Thanks for your reply Jeff. One final question, does this seem right: 1.) Remove tube 2.) Clean out and let sit in parts cleaner for an hour or so 3.) Clean off, blow out 4.) Reinstall There will most likely still be some of the parts cleaner inside of the tube, I can't see that being a major problem so long as it is as clean and dry as possible. Anything else I should keep in mind? I'm no senior mechanic! Thanks again.

yeah as long as your dpfe sensor is okay then you should be okay in no time,

Will this solution work on a 99 expidition

IT's a good bet if it's the same codes!

I have a 2000 Expedition, 4.6 L, with check engine light showing. Code is for EGR. I changed sensor and EGR valve. How do you remove the EGR tube to clean?