Ford F-150 - 1997-2003 :: Rough Idle And Poor Performance - Code P0401
Jan 21, 2016
97 4.6.. So it would appear that I have the wild goose chase of codes. The major symptoms are rough idle and very poor performance. I started off by cleaning the egr valve and ports. Then I checked the egr valve itself and watched the valve open and close under a vacuum. I was suspecting the DPFE sensor but I wanted to trying something else first. I was under the Impression that if at idle you apply a vacuum to the egr valve it would cause the engine to "stumble and stall". I did this and there was no change in the way the engine was running. So now I'm lost as to where to go from here.
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So here's the background. I recently bought this truck. It's a 97 Ford f150 4x4 4.6l 99w vin code. Anyway Driving it home got a p0401. No problem. I Applied vacuum from other vacuum source to EGR engine stalls. So to me passages are clean in the throttle body. I checked to verify and indeed passages are clean. No while doing so I noticed no vacuum was making its way to the dose valve thing. Strange.... So took the line that runs to the passenger fender to dose off and it was impossible to blow air through.
So I cut out the clogged section found solder in the line. I filled the gap I now created using some 5/32 vacuum line reconnected to test and to my anvil still not vacuum. So I disconnected it again. Went directly to where the yellow/orange dose vacuum line connects to at the passenger fender and to my surprise no vacuum there either. No my question is. Am i suppose to have constant vacuum to the dpse or I'm I just being an idiot. And two if I am suppose to when the vacuum line runs into the passange fender where does it go from there and could I have a major issue in my hands?
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On my 98' f250 4.6L 4x4 .. My check engine keeps going off and on, I finally pulled the code and its the P0401. The truck pings and knocks now and than and idles a tiny bit rough sometimes but overall runs good and gets the same mpg it always gets.....is this a bad egr valve?
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I've had a 0401 code on my truck for the last two years. I've replaced the EGR valve and the dpfe sensor a couple of times, with fomoco parts. Ive also cleaned out the egr tube that comes off the exhaust manifold. In this time I also discovered a couple of vacuum leaks and replaced those. I changed the pcv valve, tried running 93 octane gas, and had a mechanic friend run a special smoke through the vacuum lines to find more leaks. Also put a brand new gas cap. I have an obd computer and cleared the code repeatedly but the light always returns.
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My 2001 F-150 came up with this code and I changed the EGR valve cleared the code and it returned 15 miles later. The truck only has 30K miles and the warranty expired 24 May.
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Have a p0401 code which I need to diagnose and solve. However, I don't believe the symptoms are indicative of the EGR system. Its a 1999 4.6L auto approximately 200k miles. Truck runs fine until it warms up, and then occasionally it begins to act like its missing under load. steady state on the freeway it may have an occasional miss, but put a load on the motor and the miss becomes real bad. This doesn't seem to me to be symptomatic of a P0401 code, but I don't really understand the EGR system enough to be sure. Searching on the forums for other p0401 codes doesn't seem to have the same symptoms.
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Dreaded insufficient EGR flow. I've read I should clean the EGR ports.
I can't really find where these are? I took the throttle body off.
What I should do with this thing? I also get a hesitation on initial take off.
1999 F150 4.2 V6 ... 160k miles on it. Runs good otherwise.
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Has a P0401 code EGR unSufficient flow. Ive read several things that it could be, from a DPFE sensor to the EGR valve it's self our that the port going into the TB could be plugged. Truck drives fine does not have a miss or anything noticeable when driving other than the CEL, trucks a 4.6 with 200k on it. Forgot to mention it sometimes gets a P0455 code but i assumed that is gas cap. or could it be related?
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What that means? The check engine light is NOT on but I looked for a code because my truck is idling rough, and when driving, when the overdrive kicks in, it vibrates really bad. As if a bad U-joint on your drive shaft. The truck has been in a field for about 5 months broke down so any clue? Haynes manual says nothing about P1000.
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I have a p0401 generic exhaust gas recirculation flow insufficant detected code on my truck I was wondering what would be the first thing to check to get ride of this code? my truck hesitates from a stop while excelerating to several thousand rpm. should I try replacing the dpfe sensor? what does dpfe stand for? do they sell this sensor at oreilys or do you half to get this a the dealership?
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My7.3 is idling rough till I pull the fuse for the fuel pump them it will smoothen out I ran a by pass switch to us my truck but the fuel mileage is bad why
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This is a accent 2015 Sr poor performance under load and when I have passengers. This car is 1 month old. 1.6 lt.
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I have a 2000 Alero w/ 2.4 103,000 miles auto. I have been trying to fix a problem for about 3 months. It all started one night when i got stuck in my backyard in about a foot if mud. I thought i could drive it out, but when the wheels would spin and traction control would limit the rpms. After getting out the car would skip every now and then going up an incline at highway speeds in 4th gear (drive) then it would skip while idling. I could get it to run smooth if i hit the pedal and made it shift to 3rd. I drive this car daily and the problem has got worse slowly. Now its hard to crank and when it does there is a small amount of white smoke with strong gas smell while the motor spudders for about 10 secs.
It will finally "clear" up and still misfire every few secs or just cut off. Gas mileage is terrible between 15-18mpg. The engine light and trac off light has only been on twice. Both times the code was for random misfire of multiple cylinders. I have put plugs, boots (wires), distributor, 2 fuel processor regulator, seafoam, all octanes of gas, pulled injectors (looked ok a little dirty but still could be one) and I have ordered ignition control module. Its getting hard to drive and even harder to sell. It has just started the white smoke and gas smell and i think its that's the pressure regulator, but the skipping and rough idle....
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I just acquired a 2003 with 5.4 L. Did all new plugs and coils, cleaned MAF sensor, changed air filter, oil, transfluid and filter (obviously not related).
Upon start up and idle the truck has is rough, enough that it will vibrate the whole truck SLIGHTLY. Once in gear and warm, it smooths out and is fine. Unit the next stop and start.
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I got a 97 f150 4.2l from my neighbor. he takes good care of his vehicles. he sold it to me cuz it started to idle very rough like a misfire. it is hard to start when cold spits sputters and pops. once started idles like it wants to stall, then will idle normally then back to rough. back and forth like that. runs like a champ when going down the road . check engine light was on took it to auto store they checked codes . said bad o2 sensors so i changed them. still same issue. neighbor changed coil packs checked spark plugs and wire. every thing fires good. i changed iac. still didn't fix problem. could this be a bad egr valve or sensor? if so how can i diagnose this? he also thought was a clogged cat and bored it out. tight budget can't afford to take it to a mechanic. Was told spray carb cleaner spray around engine to check for leaks that did nothing at all...
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I bought this truck used and when it's in drive the engine idles rough and seems about to stall when the ac is on at a stop sign or red light.. I've tried it w/o the ac on and it seems a little better but not as smooth. Idle in park is fine.
When I should start looking? Spark-plugs? spark plugs wires, disturber cap, fuel filter etc...
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Our car's don't have as great acceleration performance when hot / after having been driven for 30+ minutes?
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I have a 2000 Toyota Corolla LE that ran very well until about a month ago. It has about 146,000 miles on it. A month ago it started hesitating from a standstill and the engine ran extremely roughly when trying to move the car. But when I put it in low gear it did much better, although not great! When in Drive it barely moved the car at all and would frequently stop running completely.
When I took it to an auto parts store they hooked it up to their computer and it read out that I needed either spark pugs, spark plug wires, or a new coil. I have replaced the plugs, but that made little difference. I then took it to another auto repair place that told me that it was either a problems with valves, or a 'problems in the lower engine'. I don't know what that latter problems means but either way it sounds like it will be very expensive to fix.
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97 chevy k1500 with 305, engine rebuilt by shop 60k ago, last few months only drove truck 4-5 times, last time driving gave p0306, new plugs, wires, cap, rotor, cleared code, now gives p0300, took intake apart removed spider, sprayed/scrubbed each injector and poppet with cleaner, but no way of cleaning the line between the injector and poppets. No change after cleaning. Also ran injector cleaner through tank. All vacuum hoses look in good order, sprayed carb cleaner around intake to check for leaks at intake/throttle body, no leaks.
Checked TPS, IAC, MAF, Coil and fuel pressure, all good except fuel pressure was 52-54 while idle, replaced fuel pump, screen filter and main filter, cleared code, rough start and rough idle still gives p0300. Checked coil with ohmmeter, between posts A & C, Chilton says 0.1 ohms, i got 0.5 ohms, went to autozone and had them check a new coil, it have 0.5 ohms......? Can drive at higher speeds and runs smooth, but idle is poor almost dies.Checked fuel pressure after pump replacement, still ~54 psi. Stumped and don't want to throw more parts at it without a proper diagnosis. Have a OBDII pocket scan tool, but can't find manual, will try to find manual and see if I can pinpoint the misfiring cylinders.
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I have a 2001 VW Passat Wagon 1.8t AUG. A couple of months ago, I took it into my shop for a check engine light. The did the following work on the vehicle:
Replaced MAF sensor
Replaced broken oil level sensor
Replaced outer CV boots
Resealed my transmission pan (it was leaking)
Replaced bad vacuum hoses
When I got the car back, it was idling really rough, and one time it even stalled. Just after starting it, when I hit the gas it wouldn't respond immediately and sputtered for a little while. Once I got going it was usually OK, unless I was going uphill...where it wouldn't perform as well and the engine noise kinda wavered. I also noticed that my gas mileage wasn't nearly as good as it used to be. (I never experienced any problems like this before they did this work) So I took it back to the shop and they replaced both the front and rear 02 sensors. I still had the same problem, so I took it back, and they replaced the fuel filter. Still has the same problem.
The light came on after a month, so I took it back and it was the random cylinder misfire code...and they said that didn't really know what to do about it. So I decided to take matters into my own hands. I cleaned the MAF sensor they installed (took it out and sprayed it with cleaner) nothing. I replaced the spark plugs and while doing so found that one of my ignition coils was bad, and I replaced that as well. Turns out the AutoLite plugs that a local parts store sold me are crap for this engine (actually caused misfires) so I went and got Denso double platinum plugs the next day and put those in. And finally I changed my air filter. Still having problems.
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2000 Ford F150 1/2 ton 2x 5.4L... Last year, I started having a problem where when the temp dropped below 50 degrees outside, my F150 would idle really rough and sometimes stall out. The CEL came on and reported some codes that I don't remember but pointed to bad air/fuel mix. I consulted a friend and he suggested changing out the IAC. I did that just towards the end of the cold weather spell we were having and the engine ran great so I assumed it was fixed.
Well, the temps have been below 50 for 8 days now and ever since the temps dropped the problem has come back. I took it to AutoZone to have the codes read and they gave me the following:
P1151 - Lack of O2 switches -bank 2 sensor 1 : ECM could not adjust fuel trim because of a lean or rich condition
AND
P0171 - Fuel trim bank one condition : The powertrain control module uses the oxygen sensor to calculate the Air/Fuel ratio of the engine. The computer recognized a rich or lean condition on one engine bank only.
Both printouts that they gave me mentioned the following:
Poor fuel pressure
Bad or Malfunctioning MAF sensor - Dirty/defective
Oxygen sensor defective
Fuel injector problem - Leaking or fuel pressure high/low
Vacuum leak on engine
I again called my mechanic friend and he suggested cleaning the MAF and if that didn't work replacing the MAF. I cleaned it and the problem was better but still not fixed.
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