I've wrote about this before. I am having an apparent problem with the Egr valve. Engine code says that it was insufficient Exhaust flow. I went and bouht a new one and after about 20 or so miles, the engine light shows back up. Hoses are new and everything. This from a Triton 4.6 f-150, 1998. Any suggestions
would be appreciated! Thanx
__________________
Paul
1998 F-150 4x4 5spd 4.6L 3door
May you ride with the wind in your hair and the sun at your back!
Head West!
I had the same code P0401 (also P1408) which both read as 'Insufficient EGR Flow'. I tested the EGR valve, the DPFE sensor and the Vacuum Regulator Solenoid and found no problems. What I did notice was that when I applied vacuum (with a hand pump) to the EGR with it running, the engine ran slightly rougher, but not as bad as it should. It should have just about stalled it. I took it off and cleaned the thing out, and cleaned out the passage into the intake manifold with a wire brush. But the light came back on. Same code...
So yesterday I disconnected the battery, took off the plastic air intake, then the Throttle Body (remove the throttle and cruise linkages and the return spring), and noticed two small piles of carbon standing up inside the bottom of the 90 degree elbow that leads to the lower intake mainfold. like 2 little black pyramids. The EGR port ends up in that elbow, so I removed it for further inspection. The ends of the passage (it splits in 2 at the base) were almost completely plugged with carbon. I took a screwdriver to them with some carb cleaner and cleaned them completely and the code is now gone. I checked it with my scanner and also verified by going to NJ State Inspection this morning. I also cleaned the carbon build up in the throttle body, as it was pretty gummed up. I'm pretty sure that's what was causing the slight hesitation I was experiencing. The throttle blade was sticking slightly. Not any more!
Be very careful when installing or removing these parts- I dropped one of the 8mm throttle body bolts down into the lower intake and almost lost it (thank god for the magnetic pickup tool, and that it lodged itself before falling under the lower intake!), and the EGR gasket fell into never-never land too, never to be seen again. I can help you avoid my two mistakes by telling you this- place clean rags under everything you are installing/removing to catch the parts you will inevitably drop. I was even thinking about not dropping the bolt when it happened...
Let me know if you have any questions if you decide to do it yourself. It's not that difficult. I don't know what your mechanical abilities are, but I'm pretty good and this took me about 3 hours total to complete, including prep and cleanup work. I didn't think to take pics, but have a pretty good memory.
I will try this this weekend! Did it improve your gas mileage? Cause mine sux! I am getting about 13 to 14 mpg's! I mean the engine seems to run fine. But I feel it should run stronger! So with that, did you notice a power increase? Thanx!
__________________
Paul
1998 F-150 4x4 5spd 4.6L 3door
May you ride with the wind in your hair and the sun at your back!
Head West!
Your problem is a bad DPFE Sensor and Ford actually did a recall on my 01 F-150 4.6L V8 after I already replaced it myself. The part is about $80 from the dealership, if it was not recalled. I'm not exactly sure how your system is set up, but it should be a little black box coming off the EGR tube. I now have an 03 with the same engine and the entire EGR system was redesigned.
A P0401 code reading 'Insufficient EGR Flow' is not necessarily the DPFE Sensor, no matter what Ford says. Just because there was a recall or 'streamline diagnosis' doesn't mean that it's definitely the problem. Proof is under my hood. (98F150 4.6 w100k hwy miles)
Several people 'streamline diagnosed' (kind of an oxymoron, huh?) my problem as the DPFE, but after extensive research and testing, I concluded that the original was working properly. As were all the other components in my EGR system. Good thing I bought the DPFE on eBay for only $20... the dealer wanted $70 something for it. When that didn't fix it, I started diagnosing instead of throwing parts at it.
There are Ford-specific codes that relate directly to the DPFE, the EGR, the Vacuum Regulator Solenoid, and the various electrical connections, as well as the P1408 'EGR Flow out of Range' code. P0401 is a general code, designated by the zero after the P, but still reads as 'insufficient EGR flow' even on cheaper Actron scanners, not some type of DPFE malfunction code.
I would have someone with a Ford Scanner module find out exactly what your Ford code is (My bet is P1408). If it is P1408, it's most likely that the 2 ports in the Upper Intake Elbow are clogged and just need to be cleaned. It doesn't necessarily mean your EGR, DPFE, or Vac Reg Solenoid is not working properly.
You can do it yourself with limited hand tools, carb cleaner and some patience. I did! See my other posts on this for details.
As for the fuel mileage, I'm not sure yet. Probably won't have too much effect on it. The EGR is meant to recirculate some exhaust gases to cool combustion temps, not really a mileage or power-related thing. From the miles I have driven so far, it looks and feels about the same. My coolant temp did decrease by a few degrees, though. I like that!
I think the biggest noticable effect was because I also cleaned the Throttle Body, as it was also full of carbon and sticking closed slightly.Once you get it off the truck you'll see what I mean. Once that was cleaned, my slight off-idle hesitation disappeared. Still can't make up for only having 3.08 gears in the rear...
Be wary of 'streamline diagnosis'... there is still no substitute for the real thing.
Hey you all! Thanx so much for all the info! I am kind of new at Ford-Trucks.com. And as soon as I figure out how to rate this stuff, You can bet your Ford Horse Shoes that I will! All of this combo of info, different strategies, and opinions is too good! Some, if not all of it has to work! Again Thanks! Now if I could only get ahold of a copy of that CD for the 98 F-150 JBabbler had or has posted, I would be set!
__________________
Paul
1998 F-150 4x4 5spd 4.6L 3door
May you ride with the wind in your hair and the sun at your back!
Head West!
Originally posted by WhipsnHorses I've wrote about this before. I am having an apparent problem with the Egr valve. Engine code says that it was insufficient Exhaust flow. I went and bouht a new one and after about 20 or so miles, the engine light shows back up. Hoses are new and everything. This from a Triton 4.6 f-150, 1998. Any suggestions
would be appreciated! Thanx
__________________
Paul
1998 F-150 4x4 5spd 4.6L 3door
May you ride with the wind in your hair and the sun at your back!
Head West!
Not sure if you had solved your EGR problem? Was your last post a question?
Are you sure it said 'Insufficient Exhaust Flow'? Was the code P0401? If so it should have read 'Insufficient EGR Flow', which is most likely due to clogged ports at the intake elbow.
to test for egr flow. use a vacuum guage and manually oper the egr valve. at idle the engine should run rough. if not, the egr passages usually in the intake manifold are plugged. if the engine does run rough. remove the dpfe sensor and see if there is exhaust flow through both hoses and check hoses for leaks. if hoses are ok and exhaust is getting through both hoses the dpfe is probably at fault.
if you remove the dpfe and tap it on something there will usually be water coming out the tubes. not always
I've got a 98 F-150, 4.6L V8 w/ approx. 75000 miles. I am experiencing pinging with acceleration but only after the engine has warmed up. No codes are present. I've cleaned the MAF sensor, replaced the EGR valve, and tested the vacuum regulator and DPFE sensor. Backprobing the terminals on the DPFE sensor with a voltage meter, I am not noticing any fluctuation in the voltage at the signal terminal as the engine warms up. I take this to mean that the DPFE sensor is bad. Any second opinions?
I replaced my EGR valve and still had the EGR low flow error; followed advice and found carbon deposits X 2 inside intake manifold. With minimal effort, cleaned and NO MORE CHECK ENGINE LIGHT!!! Thanks!
I thought that as the engine warms up, the computer signals for the EGR valve. If you backprobe the signal lead at the wiring harness on the DPFE sensor, I thought that there was supposed to be very little voltage for a cold engine but should have approximately 4-6 volts there as the engine warms up and the computer signals for the EGR valve. This is not the case?? Any other idea what could be causing the pinging as it only happens after the engine has warmed up?
at an idle there should be no more than 1.3 volts.
the egr valve will not open until the engine is warmed up.
the computer will not command the egr open until a load is present, (cruiseing) the sensor should go up to approx. 2.5-3.5 volts.
also check to make sure the dfp hose are routed to the right port on the tube had the same codes and stuff switch the hose around and no faults 250000 going strong
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EGR Whats the Deal!
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