Ford F-150 - 1997-2003 :: 2000 - Idling And Running Rough On Acceleration - P0171 Code?
May 31, 2014
My daughter returned from college with her 2000 f150 4.2 idling and running rough on acceleration. It is throwing a P0171 code only. I replaced the isolator bolts/plenum gaskets four years ago because of a P0171 & P0174 codes.
So far I have replaced the MAF, new PCV valve and elbow, checked all obvious lines for vacuum leaks (though I suspect a leak somewhere still). Also, a quick check of the plugs show some lean color/deposits on the drivers side only. Any thoughts or troubleshooting I should try next?
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I've got a 2000 f150 with a 5.4 and 135,000 miles. The other day it was driving fine then i stopped and got gas and after that it was boggy and running rough so i thought bad gas but i ran through that gas and got more at a different store. The cel came on i got it checked it was misfire cylinder 1 so i put new cop, spark plug, and injector. Unhooked the battery and then the light came back on so i ran the code and now im getting a p0171. I checked the pcv and sprayed around the intake and vacuum lines. I also checked the pcv hose and elbow in the back and i found nothing its a fairly new hose. So, it does run rough it shutters a lot.
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It's been a long time since I have posted here mainly because my truck was wearing a bow tie for awhile. But my wife was nice enough to tell me the Bow Tie wearing truck was making a funny noise on New Years Day (seems a small drum corps took up residence in the oil pan). So anyhow now I am back in a real truck . My new to me 1998 F150 5.4 Liter ran fine until yesterday. It started idling rough and almost stalling at red lights. about halfway home the CEL light came on and is throwing a P0171 code.
So far I have checked for vacuum leaks including all the elbows on the PCV system' tried the spray test with a can of flammable break fluid and a can of starting fluid (man I love the smell of that stuff) could not find a leak. Cleaned the MAF sensor and the K&N air filter (not a fan of these) IAC seems to be working. Only thing I know that is leaking for sure is the driver side exhaust after the cat. But that is the wrong bank if I am correct on which bank is which.
So why only one bank running lean and why does it act like it is only firing on 4 cylinders?
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I have a 2000 Ls 3.9 V8 125,000 miles that started idling rough.I checked for codes and got p0171 (bank 1 lean), p0175 (bank 2 rich) and p0307(cylinder 7 misfire). I swapped cop and sparkplug from cylinder 7 to cylinder 5 and erased the codes.I ran the engine for a while and rechecked the codes to see if the misfire followed the cop and plug. They did not. I still get p0171,p0175 and p0307 (cylinder 7 misfire).
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97 F150 4.6 Vin 6, 5-Speed Trans, 200,000mi, Rebuilt recently. I was on my way to get my truck smogged, but she threw a code, P0171. I read somewhere to clean the throttle body elbow, which I did (needed to do it anyway). After I had everything put back together, I start her, and it's rough and immediately dies. If I keep the RPM's at about 1.5k for a minute, then let off, the truck will run fine for about 30-45 seconds, then die again. I just replaced my IAC and the problem persists.
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I have a 2000 f150 with 5.4 Triton with 165k miles. I did invest in a code reader. It started missing and code P0302 came up along with P0171. Put new coil on #2 and truck ran fine for a few days. Then it started to run rough again. Shaking, Idle rough, no power and CEL came on again. This time code P0171. I changed out fuel filter to no avail. My next step was to start looking for vacuum leaks. As I'm searching, All I am finding is trucks with this problem also get P0174 code. My question is since I am only getting lean on one bank does that pretty much eliminate things like MAF or the famous elbow vacuum leak and make something that only affects one bank like an O2 sensor on CAT more likely?
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I replaced the heater core in my truck this weekend. The only thing I was worried about was pulling the dash. The truck is a 1998 f150 with the 5.4.. Everything went fairy well and decided to replace the AT Shift cable as well. Got everything put back. Truck runs, no leaks, no antifreeze smell. After running about 20 minutes, it started idling a little rough and my check engine light came on.
The codes are p0136, p0156, p1131, and p1151. I know these are related to the OS sensors. My question is could it be as simple as I miss an electrical connection when putting the dash back in? Was thinking possibly somewhere on the passenger side under the kick plate or possibly something while hooking up the heater hoses? Maybe even a ground that didn't get connected back when putting the das back in?
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I just started to have this problem yesterday. Engine light comes on and stays on. Engine shakes and truck won't go over 50 MPH. Autozone code checker came up with P0171.
Truck has about 95K miles and I had the spark plugs replaced at 75K miles.
Transmission was rebuilt at around that time also.
I only drove it to Autozone and back today to post the code and see what everyone's opinion is as to what's wrong.
Here's what the printout says : P0171 "Fuel Trim Bank One Condition"
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Just got a 98 f150 w/ 5.4 4x4 excab. It idles fine but under light accleration. It starts bucking and missing bad, if I step on it, it down shifts and accelerates fine. If I try to maintain one speed it misses bad. It is not throwing any codes right now. The check engine light did come on for like a minute but went back off before I could have it read. I hooked up a scanner just to see if any codes were stored and got p0300 and p0301. I am going to clean the MAF and check for vacuum leaks. I hear the rear plug and coils can get water in them causing similar problems.
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I have 2007 explorer with the 4.6 V8....
Recently it started running horrible. Rough idle, drives badly, hesitation, etc. Check engine light is on, code P0171. I cannot find a vacuum leak, and i am pretty much at a loss. Before it started running poorly i replaced the thermostat, and flushed the coolant. I am assuming this is a coincidence.
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Here is my situation : I have a F150 1999 4x4 ext cab with 326 000 km. A little while ago I got a P0401 code so I decide to clean the TB first and at the same time change plugs and wires since they were overdue. The same code came back and a misfire. Ordered EGR valve, DPFE sensor and selenoid. Realize that I had ordered crappy plugs by mistake. I change all plugs. Had to wait for the EGR valve and others to arrive. I drove the truck for a while since I did not have the time to change the valve and others, during that time the misfire did not come back. Yesterday I change the EGR and others. Today I get a truck that runs really rough and got new codes , P0305 and P0174. I'm really confused now on what should be my next step, should I change the coils, can a P0305 cause a P0174. Should I change vacuum hose going to the EGR , selenoid and DPFE.
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I started out with my 2000 F150 with a 5.4 V8 running rough at idle. It would idle way down slow and then rev up a little over and over. On a couple of occasions it would even die when in drive or reverse. I did finally get a Check Engine light so i put it on my diagnostic program to see what was up. Here is what I got:
P1151 Lack of HO2S21 Indicates Lean
P0171 System Too Lean Bank 1
p0174 System Too Lean Bank 2
After doing some reading up I checked all my vacuum hoses and cleaned my mass air flow sensor. I then got the same codes again after a few minutes of running. So I went to the next thing that was recommended, the upstream bank 2 O2 sensor. After changing it the truck ran fine for a couple of days, no issues. Then all of the sudden it idled a little funny again and I got a Check Engine Light again. This time:
P0171 Bank 1 Lean
P0174 Bank 2 Lean
P0300 Random/Multiple Misfire
I reset the light to see if I would get the same again later. Before the light came on again I filled my truck up with gas and it seemed to be running pretty good again. Then a day or so later it set the light again. This time:
P0171 Bank 1 Lean
P0174 Bank 2 Lean
P0136 O2 Circuit Malfunction Bank 1 Sensor 2
P0156 O2 Circuit Malfunction Bank 2 Sensor 2
P1131 Lack of Switches HO2S11 Lean
P1151 Lack of Switches HO2S21 Lean
I went ahead and drove for a few days as it had gotten really cold here and I didn't feel like messing around in my shop since it isn't heated. A couple days ago I needed gas so i filled up again. Suddenly the problem was gone again. Truck ran fine idled fine no missing or odd idling at all. That lasted a day or two before it started acting a little weird again. At that point i was down about 1/8 of a tank from full. I have read that there can be issues with the fuel pump.. I am kind of wondering if that may be it now. But I haven't had to deal with this sort of issue before so I am unsure what to check next. The truck always runs fine off idle, it only seems to have the issue when it is idling. I had reset the codes the last time and i have the light on again now. I haven't checked it yet but I am sure it is going be some combination of what i have had in the past.
I have read that the IAC valve can be an issue as well. I had a problem with mine sticking a couple years ago and when it would do it you could just tap it with a wrench and it would idle up. But it never died like it does now and it would also idle a lot slower than it does. Back then I cleaned the valve and had no more issues with it. The truck has always had times when it would act weird at idle usually after slowing down after being at highway speed. The current issue happens at all temps cold or hot.
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I have a 2003 F150 4.2 with 155000 miles. What may be causing this?
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I've had this problem for a little while now, my 97' F150 V8 4.6L, has been running real loud and heavy. When it starts up it sounds like a race car. It finally shot me a code for P0171 - Bank 1 (passenger side) running too lean. From what I've read, this is most likely a vacuum leak but I don't know too much about it.
A couple of things I've noticed while driving it around:
1. If you are in the engine compartment while its running, you smell the excess gas on the passenger side of the truck.
2. The exhaust also smells really heavy
3. The loud and heavy running is mainly when accelerating, if I maintain a constant speed at for a little while it almost starts to run normal. Cruising down the highway its almost just as quiet as before the issue
4. Engine coolant heats up much more quickly, but doesn't get above operating temperature (read from tuner, never above 200 degrees)
In response to the problem I replaced both the O2 sensors closest to the engine and the PCV and elbow. No change. Have a fuel filter ready to install, but for some reason I don't think that is it either, as it would probably effect both bank 1 and 2.
Like I said I'm not too well versed in the vacuum system but if any of these symptoms stand out I'd love to hear your thoughts.
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The "service engine soon" light on my 2003 F150 Supercrew 4.6L (225k miles) just came on. The code it's throwing is P0171.
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1999 xlt with 5.4 lt p0171 only. it started with what felt like a misfire or hesitation and rough idle. Extremely rough at 40-45 mph. but with no misfire codes just p0171 so all 8 coils and plugs and sparks replaced twice in one month. and still same code tested fuel pump pressure 28 psi.... removed clogged cats, still same code... new pcv valve and elbow.... checked for air leaks around intake and intake manifold and nothing.... cleaned mass air flow sensor...I can unplug any coil on bank 1 and it wont make a difference. But if I unplug any bank 2 coils and engine makes a difference.
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I am still battling a p0171 code on my 2000 f150 5.4. I checked the fuel pressure at idle it sits at 31. I remove the vacuum line off the regulator it goes to 41. When i give it throttle when in gear it will maintain at 30. And when I shut the vehicle off completely it will maintain 38. Just looking to see if this is correct numbers. I was trying to determine a weak fuel pump.
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97 F150 4.6 200xxx on recent rebuild. My truck is throwing P0171 & P0174.
I think I tracked it down to leaky IAC and EGR gasket. I sprayed both with carb cleaner and the RPM's dropped.
My question is, wouldn't the RPM's rise instead of drop? I was under the impression that they would go up if the gaskets were leaking. Or did I use the wrong spray?
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I had my fuel system cleaned by the dealership last weekend and I feel like I gained 50hp+ ... Now its throwing a P0171 about a week and a half later. My computer also listed P0174 under the pending codes or whatever the section was.
2003 F150 5.4L ... I cleaned the MAF sensor a couple weeks back which stopped a rough idle and I have put some 300+ miles on it since. about 200 miles since the fuel system cleaning.
I got home and popped the hood and it sounded like a vacuum cleaner. Guess it is a vacuum leak. I might need to stop using this ford house. I swear this is the second time there was a vacuum leak(I think, first time they said it was spark gap issue). I'll be heading back in the morning now.
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P0306 (ok #6 missfire) with P0171 & P0174 --- Do I chase electrical or fuel or both. Afraid to assume anything but probably would normally address the misfire electrical first.... Don't want to go down that 'primrose path' if others have been there first!
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I just bought a 99 f150 and the check engine light came on with code p0171,system too lean bank 1. It runs and drives fine but has a strong smell of gas when I shut it off.
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