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Just replace egr valve and dfpe valve as well as cleaning throttle body to try and remove 401 error code now the engine idles faster and 171 and 174 codes are showing up any ideas thanks g.

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171/174 too much oxygen in the exhaust, sounds like you may have a vacuum leak after the Mass Air Flow sensor (MAF). Check for leaks in the intake system. Also the MAF sensor could be dirty, clean with electrical cleaner and make sure that it is completely dry before hooking it back up and testing it. Hope this helps, let me know.

Posted on Aug 23, 2010

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98 cantour svt code 401

It basically indicates a problem with the EGR valve or the DPFE sensor. Usually, this is caused by blocked passages in the EGR system, not with the EGR valve or DPFE sensor themselves. To clean them, you will have to remove the throttle body.

Mar 25, 2013 | Ford Contour Cars & Trucks


DFPE Differential Feedback Pressure Exhaust sensor

<p><b><span>1.7) <span> </span><u>DFPE - Differential Feedback Pressure Exhaust </u>(sensor)<u></u></span></b><br /> <p><b><u><span><span> </span></span></u></b><br /> <p><b><span>What is it?</span></b><span> This is an electrical device that measures the differential pressure between two ports on the pipe that supplies the exhaust gases to the EGR.</span><br /> <p><span> </span><br /> <p><b><span>Where is it located?</span></b><span><span> </span>The DFPE is located near to both the EGR and the exhaust feed-pipe to the EGR.<span> </span>THE DFPE makes two piped connections to the exhaust feed-pipe in front of the EGR valve</span><br /> <p><span> </span><br /> <p><b><span>How does it work?</span></b><span><span> </span>The two pipes on the exhaust feed-pipe are connected at two separate sites.<span> </span>When exhaust flows through the feed-pipe it creates a differential in pressure between the two ports and the DPFE detects this and responds by altering a voltage output to the ECU.<span> </span>The ECU is able to detect for how long and by how much the EGR is open by monitoring the DFPE output.<span> </span>Until the engine has warmed the DFPE signal should indicate no EGR activity as the ECU disables the EGR from opening when coolant (engine) temperature readings are low.<span> </span>The EGR is kept closed by either the ECU not sending voltage to the EGR actuator (in cases of direct motor/solenoid control of the EGR) or by not charging the <b>vacuum control solenoid valve</b> on the vacuum line to the EGR (in cases where vacuum is used to actuate the EGR). <span> </span></span><br /> <p><u><span><span> </span></span></u><br /> <p><b><u><span><span> </span></span></u></b><br /> <p><b><u><span>Symptoms of faulty DFPE</span></u></b><span> </span><br /> <p><span> </span><br /> <p><span>The DFPE may misread the differential pressure leading to the ECU opening or closing the EGR valve at the wrong time.<span> </span>The symptoms mimic very much the effects of a faulty <b>EGR</b> namely:-</span><br /> <p><span> </span><br /> <ul> <li><b><span>Erratic idling</span></b><span> - if DFPE signals 'no pressure' in error and ECU opens the EGR valve.</span></li> <li><b><span>Misfire ('pinking')</span></b><span> - if DFPE detects 'pressure' in error and ECU keeps EGR closed. </span></li> </ul> <p><span><span> </span></span><br /> <p><b><span>Note:</span></b><span><span> </span>Sometimes a DPFE fault can be misdiagnosed:<span> </span></span><br /> <p><span>1) If the <b>coolant temperature</b> sensor is at fault and sends an incorrect 'the engine is warm' signal then the ECU responds by opening the EGR valve prematurely causing the engine to stumble and stall.<span> </span>This pattern looks very much like a fault from the DPFE when in fact the DPFE might be working perfectly.</span><br /> <p><span>2) If the <b>vacuum control valve</b> fails to open when instructed.<span> </span>Apply 5 volts between the socket pins on the valve to check for valve opening.<span> </span></span><br /> <p><span> </span><br /> <p><b><span>How to Check?</span></b><span> Applying pressure to one or the other ports on the DPFE should result in a change in electrical output as detected by a volt meter.<span> </span>No change in voltage output indicates the DFPE is faulty.</span><br /> <p><span> </span><br /> <p><b><span>How to Fix?</span></b><span> Make sure the pipes to the DFPE are free of leaks and clear of carbon deposits.<span> </span>If the DFPE is itself faulty then it must be replaced.</span><br /> <p><span><br /></span><br /> <p><span><b>NEXT 1.8) PCV Positive Crankcase Vent valve</b></span><br />

on Jul 15, 2011 | Mercedes-Benz E-Class Cars & Trucks

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1998 Ford Escort - P1405 Error code

Follow the link for help with this fault code P1405 Ford DPF EGR Sensor Circuit High Voltage Detected

I suggest you replace the EGR valve position sensor.

Mar 10, 2017 | 1998 Ford Escort

1 Answer

Ford Escort P1405 Error Code

Are you sure you have EGR flow?? Hold the EGR valve open the engine should run poorly, if not you have no flow.

May 31, 2012 | 1998 Ford Escort

1 Answer

2001 taurus dohc codes 171 and 174 replaced MAF, DPFE and IAC. New plugs and wires cleaned throttle body and egr valve. Has high idle, surging on highway. Disconnect the IAC and it runs perfect,...

There is a large vac line coming straight down from the throttle body that goes to the PCV system. See if it has a hole in it. It is likely sucking air.

Jul 17, 2010 | 2004 Ford Taurus

1 Answer

Have a 401 code have changed all emission parts and cleaned throttle body any solution

Engine size? year? This code is for insufficient egr, usually caused by clogged egr passeges or a bad DPFE sensor. Open egr valve, if the engine idles real rough or stalls, replace the DPFE sensor. If the idle does not change, then take the egr valve off and clean the passages. You cant just keep changing parts hoping you get lucky and change the correct one.

May 24, 2010 | Ford F-150 Cars & Trucks

5 Answers

My 04 f150 had a rough idle and would sometimes stall out. dealer said it was throttle body so I replaced. The idle is still rough but it it doesn't stall. Could it be a coil pack? if so do I need to...

I have a 2005 f150,with a 4.6 and it idles rough and when you turn on the ac it wants to die. Checked the codes and there are no codes.Any suggestions?

Apr 30, 2010 | 2004 Ford F150

2 Answers

1997 ford f150 just had egr valve replaced.. engine is hesitant and check engine light is on with error code 401.. whats the prob?

Everyone says to test out your DPFE sensor. This controls the flow of the egr. When the codes pull up, everyone thinks its the egr, but really its this little guy.
Take it by a shop and see if they can mess with the bugger. They usually run about $50+.

Feb 04, 2010 | 1997 Ford F150 Regular Cab

2 Answers

Starts idol rough and dies says running with rpm up let off it dies

do you have a check engine light on? if not try cleaning the throttle body follow the tube from the air cleaner box to the throttle take hose off open throttle plate and clean with carb cleaner and a tooth brush and a rag car will run rough after you do this may have to hold throttle open to start

Jun 15, 2009 | 2000 Pontiac Grand Prix

1 Answer

Car stalls when you put it in gear

Clean out the throttle body if you get a chance, You might be surprised how dirty it gets in there. 
Try looking below the throttle body mounted to the intake,you may have to remove the snorkel that goes between the throttle body and the air filter. I believe that's where your EGR valve is and it may need to get cleaned too or replaced, you might also try removing and cleaning your idle air control.

The idle air control is mounted on the passenger side of the intake,at the very end of the intake. make sure the engine isn't hot when you remove it because two of the rubber hoses have coolant from the engine in them and if it is hot it could spray you. I sprayed CRC throttle body cleaner on mine and it cleaned it up pretty good. also be careful not to turn the adjusting screw on it as you could make your idle worse.

You can check the EGR to find out if it is bad or plugged,with the engine idling reach under the body of the EGR valve and push up.if it is working the engine should try to die when you do this. I would also check to make sure there are no cracked or broken vacuum cracks or leaks in the snorkel going to the throttle body and with the engine running tap on the top of the maf sensor with your knuckles,if the idle changes than your maf sensor is probably bad. you can unplug the wires from the maf sensor with the engine running and if the idle doesn't change then its bad. These engines are temperamental,for instance they have to maintain vacuum in the engine to run properly_something as minor as the seal on the oil cap allowing air into the valve cover will make it run poorly. Have you checked for any codes or is the check engine light coming on?

Good luck and hope this helps.

May 13, 2009 | 1990 Nissan Stanza

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