P0401 code on 96 Ford Taurus

waht about the circuit form the dpfe to the pcm? Have you removed the throttle body and cleanned those ports?

I checked voltage from the pcm to the dpfe sensor connector. I get 5V. I did not back probe it yet. I have not cleaned the throttle body ports. I removed the new EGR valve and tried to clean out the EGR pipe and intake manifold port with carb cleaner and a hanger. My buddy thinks I have a clog in the EGR pipe to the exhaust manifold.There is exhaust coming out of it. I do not know what the flow should be. Under throttle it blows fairly well. I applied vacuum to the EGR valve with the car running and it changed the idle a little. How should the car run with vacuum on the EGR valve at idle? Thanks, Fred

It should stall it, if it only dips the idle down then something is plugged!

Thank very much for the reply, Jeff. I am kind of lost as to how to fix this problem. Is there anyway to clean the EGR pipe without taking it out. In which case I should just replace it. I just checked voltage at the EVR solenoid connector from the PCM and I get battery voltage (12V). I check ohm's at the connector on the solenoid and get 34 ohms (range should be 30-70). I checked the DPFE connector from the PCM and got 5V. It seems like all the components are working properly and your right, something seems blocked. Fred

...also, would a bad Catalytic converter cause a problem? Fred

not that code!

Thanks for the reply Jeff. I am wondering if there could be any other clogged spots in the EGR system. I have been zeroing in on the EGR pipe only. Could the DPFE sensor tubes from the EGR pipe also be clogged. What worry's me the most is I do not know how long the EVR solenoid was broken off and melted behind the engine block. With that not working the EGR valve was not working properly and I don't know what kind of damage was being done to the engine. I was looking at the EGR valve when I got home and started the engine. There is a new knocking sound now that was not there before. Wonderful!!! Thanks Again, Fred

Jeff, I was looking thru the other posts for more info on the P0401 and found one you posted to another person with the same code. You mentioned that you should be able to stall the engine with about 10-15 in Hg of vacuum. I just tried up to 25 inHg and could not get it to stall. The idle changes a little but does not stall. Thanks, Fred

hi fred, sounds like you're covering a lot of bases, good tries, inmy experience, almost all 0401's are a result of bad dpfe's, vac sources or wiring. you read 5 volts at the dpfe, thats your reference voltage, you should get another voltage, around 1 volt on the other ckt at the dpfe, key on, engine off, if it doesn't read 1,find out why, if it does make sure you're 2 rubber hoses are free flowing, i've seen them burn up inside and not flow, blow them out, make sure they are not reversed, smaller inside diameter to smaller ports on sensor,etc, some engines don't stall when egr is applied, this is one of them, also you'll want to make sure you go the right updated sensor, there is diffeent styles=different calibrations. so you have a scan tool that reads live data.

Thanks for the reply bear. The DPFE sensor is the new updated plastic one. I have read the new part is F77Z-9J460-AB. The part I got was F77E-9J460-AB yet the box says F77Z-9J460-AB. I am told by the place I bought it, Szotts Ford Parts in Michigan (I bought it on ebay), that the parts are the same. Just engineering number difference's. The hoses came with the sensor and they are brand new. I have the small hose to the small port and big hose to the big port on both sides. The 5V readings are on the outside pins of the DPFE connector from the PCM. Should there be an ohm reading at the DPFE pins? Like I said previously. I have not tried to clear the DPFE tubes going to the exhaust. Thats next. Fred

thats the proper sensor, to check the metal tubes remove the hoses and start the car, you should feel exhaust blowing out both pipes, also, make sure theres no leaks in the pipe assy, even very small ones. to check the voltage on the sensor go from the middle pin to the outside ones, one at a time, on one side you should get 5 volts, on the other @1 volt.

Thanks for the reply bear. I'll check that today. I am pretty sure I checked the voltage on both sides and they were 5V. I am biting the bullet and getting the car inspected. I will clear the code when I drop it off and hope for the best. It's due by the end of this month for an inspection. Worst case I find out what the problem is. I need a new car anyway, maybe this is the push I need. I was hoping to get it to pass so I would not be rushed into buying a new car. It just pisses me off I can't figure this out. Thanks, Fred

My 1999 Taurus DOHC 3.0 kept throwing p0401 for 3 years. Replaced and cleaned all the obvious parts. Finally pulled off the throttle body and pulled off the metal-looking gasket on the intake manifold. The gasket at first look appears to be part of the intake manifold but it is not. Behind the gasket is a U shaped port that allows air flow from the EGR valve to the intake. This U shaped port was packed full of carbon and blocking all flow. Problem hasn't come back in over a year, turns out I didn't need to change any parts at all, just clean out the carbon. This cleaning CANNOT be done by shooting carb cleaner or compressed air through the intake where the EGR bolts on, you have to scrape it out.

My 1999 Taurus DOHC 24V 3.0 kept throwing p0401 for 3 years. Replaced and cleaned all the obvious parts. Finally pulled off the throttle body and pulled off the metal-looking gasket on the intake manifold. The gasket at first look appears to be part of the intake manifold but it is not. Behind the gasket is a U shaped port that allows air flow from the EGR valve to the intake. This U shaped port was packed full of carbon and blocking all flow. Problem hasn't come back in over a year, turns out I didn't need to change any parts at all, just clean out the carbon. This cleaning CANNOT be done by shooting carb cleaner or compressed air through the intake where the EGR bolts on, you have to scrape it out.