Ford F-150 - 1997-2003 :: Code P0171 And P0174 - Vacuum Leak
Apr 15, 2014
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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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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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'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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2001 F150 5.4L Triton Motor. Everything seemed o.k. then got the Engine Service Light. Checked with reader and above codes only appeared. Read numerous articles/videos and pulled the PCV hose/boot assembly and replaced the whole thing with oem part. Visually checked for disconnected tubing = none found. After this and with the new hose assembly in place I performed a reset. With the scanner still connected restarted engine and read values: ST FTRM1&2 = -.08~+2.3, both oxygen sensor voltages are varying and the LT FTRM1&2 hang around +26 and +28.
From what I understand the ST seems o.k. but the long term is WAY OUT OF WHACK. Started it up again and took carb cleaner spray and covered all the connections I could see = no change in engine rpm. No cracks in the air cleaner body. Big plug to the MAF was inserted and plugging the hole. I am thinking of making a smoke "machine" and trying that or removing the hoses from the throttle body and plugging the holes in the throttle body and see if that clears them up. IF it does then connect one by one and keep checking the values. Lot more work but I am at a loss.
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2002 F150 - 5.4 ... So just bought this truck about a month an a half ago. No problems but the other day the SES came on. It is showing P0171 and P0174. And P0000 (almost forgot that one) was told that's generic though. Haven't really noticed a difference in the way it's running. Has been extremely cold here in WV but the only thing I can notice (or think I notice) is the gas mileage has gone down a little. After reading some on this forum I'm looking for a vacuum leak correct?
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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 99 f150 with the 4.2l v6 with a 5 speed 173000 miles. I picked it up not to long ago. When I first got it it had both the P0171 & P0174 lean on bank 1&2 it was also siting for a while. I replaced the fuel filter which was filled with black fuel, also changed the PCV valve, cleaned the MAF sensor, and changed the oil. I cleared the code, drove it for a little bit and the light came back on after 20 miles.
I then proceeded to replace the upper and lower intake manifold gaskets. Upon doing that i noticed that i was missing one of the linkages for the IMRC. I went to the junkyard and pulled off another linkage rod off the same motor. ordered new plastic clips, put the IMRC on cleaned everything up and began putting it back together. I also cleaned the Injectors while i had them out as well and put in new spark plugs and wires.
Put everything back together. code was cleared since the battery was disconnected. drove it and then the engine light came back on again. this time it was only the p0174. so i then both the upstream and downstream O2 sensors on bank 2, reset the code and it came back on again. I'm lost.
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I'm getting the p1131 error on my 2000 xlt f150 5.4l. I know it's usually a vacuum leak on the pcv hosing, which I did have at the back and replaced as well as other softer joining sections(3 to be exact lol), but I'm still getting this error. Changed out my plugs and cops(as they needed it) and the back two plugs on both bank 1 and 2(plugs 4&8) were both white! Since this is an obvious indication of a lean burning cylinder can I make the assumption my most likely problem is dirty fuel injectors on those cylinders?
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I am having a difficult time trying to fix my CEL issue, The vagcom scan says P0171 & P0174 Lean banks 1 and 2. I don't believe both O2's went out I have Checked and cleaned the MAF Sensor did a quick vacuum leak inspection and all seems good. I have a GIAC ST 1 and an AFE intake with noise pipe delete. I can reset it but it returns after a day or so.
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2003 Sport Trac. My car was not starting, told my fuel pump, replaced twice and nothing. Found out about inertia switch and changed it, now car runs.
Before this switch blew out my car was running perfectly, no check engine, nothing. Now i have changed my fuel pump twice and put a brand new fuel filter in and soon after i get lean codes P0171 and P0174. My fuel pressure is 60psi at idle and drops to 0 after about 30 seconds when the car is shut off.
A lot of my intake is new since i did have a vacuum leak before, so i do not suspect that is it, especially since this happened after the new fuel pump. I am completely stuck as to what i should do. And i get hesitation when trying to accelerate sometimes
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I was coasting down a steep hill yesterday when the CEL came on. I pulled the code this morning and got code P0174, system too lean bank 2.
I cleared the code. Should I just wait to see if it happens again? The truck is running great. There is no sign of a problem. BTW, it's 99 F150 5.4.
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So the past few weeks my truck has been sputtering a lot. It seems to do it more so in low RPMS but when I lay on the throttle I didn't really notice it. I haven't had time to look into the issue but yesterday the issue got drastically worse and the CEL finally came on. Registered P0174 as well as a number of other codes including misfires on 7 of the 8 cylinders.
So far I have replaced the fuel filter. Spark plugs are only a few months old. I didnt think it would make sense for all of the coil packs to go out at once so I was thinking either a fuel issue or vacuum leak. Why would it only spit out P0174 (Banks 2) and not show P0171 (Banks 1) along with it? Fuel pump? Vacuum leak? Where should I start? 2002 F150 5.4L...
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I have a 1999 F-150 with the 4.2L engine. I recently did a motor swap as the original motor was bad. I bought this truck as a project truck and have enjoyed working on it.
When I did the engine swap back in May of this year, it took a while to work out all the little bugs and quirps. However, after a while of running the truck it threw a few codes. I replaced a lot of the emission components and no more codes for several months until last month the truck started throwing the infamous P0174 "too lean bank two"... I have replaced the pcv valve and all the hoses to include the little rubber boot under the front of the intake, all 4 O2 sensors, MAF sensor, EGR, DPFE, IAC valve, new wires and plugs to include coil pack, fuel pressure regulator, and all the vacuum lines that are under the hood.
The truck runs fine, has power, but about every couple weeks or so it throws this P0174 code. I know there are alot of threads on here about this problem and I have read many of them. It only throws the P0174 and not the P0171. I am wondering if there could be a problem specific to "bank 2" that I am over looking.
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I have a 2001 F150 XLT Supercab,4.2lt, automatic, 2WD.
I was able to start it about a month or so ago but it was really hard to start. I had to use starting fluid to get it started, and it was still tough to get it to start, but once started and warmed up it ran fine.
Now I tried to start it again and it kicks over and wont start. I tried the same with the starting fluid and it almost starts and dies. I think I used a little too much starting fluid because after a while of trying and spraying starting fluid, I got a hard backfire that sounded like a shotgun that was strong enough to pop off the MAF Sensor and throw it about 10 feet. I nearly crapped my pants! It looks clean and undamaged but I hope I didn't damage the MAF Sensor when if hit the ground.
The truck sounds like its starving for fuel, so I'm not sure if the fuel pump relay is going or has gone bad, or if its the fuel pump. How to check these items without making it a huge project to diagnose?
Once I can get it to start easily, I have a couple of questions about the trouble code that keeps coming back P0174. That was the original problem with it before the starting problem.The diagnostic says that it is lean in bank 2 but a mechanic friend of mine said something about a vacuum leak.
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Wife took truck out and turned around after going less then a mile, saying it was running very bad. We got this truck about two months ago at a state vehicle auction. It was a state used truck, 145,000 miles, 05 Ford F350, ext cab and 8' bed. Anyway at first I thought it was valve tap until research said an exhaust manifold. With a fog machine in rear exhaust pipe we confirmed it was leaking and replaced the exhaust manifold. Figured it was probably a good time to replace spark plugs too. Took truck for a ride and she still buck and farted.
Got a code machine and got P0171 and P0174. Couldn't find a vacuum leak, but your could hear the air being sucked in. went to local parts store, guys couldn't find leak, but they said truck sounded like a steam machine. today I made a homemade smoke machine and smoke came from air intake, figured the gaskets were bad. The pictures show what I saw when I took the gaskets off. The port that has melted is the same port were the exhaust manifold was leaking from. Am in deep "doo-doo". What caused this?
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I have a 2003 F150 4.2 with 155000 miles. What may be causing this?
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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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2003 Ford Explorer, with P0171 and P0174 codes, common problem, as I have read. I pulled the cover over the engine off, and I immediately found the likely problem. There is a hose/connection that runs from the valve cover on the right side, about 6 inches behind the oil fill tube across and looks like it comes into the Carb. Where it turns to come into the carb is a rubber elbow. This elbow has a hole in it. Temporarily I have used electrical tape, but when I run the vehicle, I see the elbow begin to collapse. I believe the elbow is getting weak with age, plus the hole/tear doesn't work. Anyway, what i the part number, or what this is called. Hoping Advance Auto, or Napa will have it, just don't know what it is called, and can't figure out the part number. Otherwise I will pull it off tomorrow and take to advance and see if they can match it.
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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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