Ford F-150 - 1997-2003 :: 2003 - Got Code U1262 - Random Misfire?

I have a 03 F150 with a bi-fuel 5.4 engine an it has 195000 miles. I have had trouble for some time now with misfires. I bought the truck in october of 2011 with 125000 miles and replaced all the coils and spark plugs because it was misfiring badly will running on CNG. It was fine on gasoline and never had any codes. After I replaced the plugs and coils it ran fine on CNG and gasoline.

This summer 2013 it began missing badly at highway speeds only when running on CNG. If I accelerated the miss would go away until I was light on the throttle again.I checked the misfire count and found the bad cylinder and replaced a coil. Then a day later same thing on another cylinder. I swapped a coil from another cylinder and problem went away for a day. Eventually I chased the misfire around all the cylinders on the engine until I had ended up either replacing a spark plug or swapping a coil on all the cylinders. And I still had a misfire. It seemed to be worse on days with temperatures above 90 degrees. Eventually I got it to stop misfiring.

So now 5 months later I am back again with a misfire. This time it is misfiring on both gasoline and CNG and under any throttle conditions, except coasting. I have no codes. And the misfire monitor is sending me around the engine again. I have replaced a spark plug in two cylinders and swapped 4 coils.
I'm ready to buy all new coils, but I want to be sure that it is not a waste of money since the old ones only have 70000 miles on them.
Two days ago I had the misfire monitor saying #4 in the evening and the next day without me having done any work on it it was saying #6. Later that same day it said #7 and I still hadn't done anything other than drive the truck.

I checked the connections at the firewall on the drivers side with the three large plugs that are held in with a 10mm bolt, they looked fine, no corrosion or burnt pins. I checked the connection at the ACFM which also looks good. I will check the connection at the PCM in the next day or so.

Some other problems that may be contributing:
1. I occasionally get a U1262 code (scp fault)
2. Sometimes when I check the misfire monitor it only shows 7 cylinders, sometime 9 cylinders. I am using an Innova 3160 scanner.
3. I have either a leaking valve cover gasket or leaking head gasket, because I have oil dripping from the rear bottom corner of the passenger side cylinder head right above the exhaust pipe.

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Ford F-150 - 1997-2003 :: OBD II CODE P1450 - CEL - Fix?

Had to put a new tranny in my 1997 F150 XLT Lariat 4x4 5.4 liter engine about 3 weeks ago and now have gotten the check engine light. Took it to autozone and code 1450 was the only code listed. They said it was was a vacuum problem, but when I checked the code at a web site it is listed as a secondary air injector system circuit shot to B+.

My question is which is correct and how to repair?

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Ford F-150 - 1997-2003 :: Got Code P0171?

I have a 2003 F150 4.2 with 155000 miles. What may be causing this?

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Ford F-150 - 1997-2003 :: SES Light Is On - Code P0171

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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Ford F-150 - 1997-2003 :: 2002 - Has Code PO125?

truck runs good just has po125 code

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Ford F-150 - 1997-2003 :: 1998 - CEL For Code P1747 Comes And Goes

1998 F150, XL, 4.6, auto 138k miles. Idles perfect, give it gas 1 time, fine. Second time it sputters. Third time it sounds awful but will Idle perfect. Put in drive, bucks, sputters, jumps, and damn near dies. Threw code P1747 EPC solenoid. Next day truck runs perfect check engine light goes out. Two weeks go by starts to sputter again and check engine light comes back on. Bad ECM?

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Ford F-150 - 1997-2003 :: 1999 - CEL Is On / Code For Cam Sensor Bad

I have my dads 99 f 150 cel light is on. Scan came back with code cam sensor bad replaced the sensor and the light cam back on now I got 2 pages of codes from plugs and wires coil pack fuses, wiring harness to all O2 sensors to cats to even replace the engine and computer, where to start at. The bad think is i got to get to codes off and truck working with no light for the state to inspect it and get his tags. or the truck will have to be crushed, and i have 2 weeks. By the way 4.2 liter and manual trans.....

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Ford F-150 - 1997-2003 :: Bank 1 Too Lean Code

Well I got the ubiquitous "Bank 1 Too Lean" code this morning. Yesterday I changed out the PVC Valve, Elbow and Hose assy.

I changed out the hose from the intake to the canister purge valve on the firewall next to the master brake cylinder, that one was like dust.

Today I'm changing out the rear O2 sensors, but I may change out the fronts when they get them in (very rural area hear).

I'll keep looking for vacuum leaks and change out the MAF sensor. I hate to think it may be the intake....

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Ford F-150 - 1997-2003 :: CEL On With Error Code P0155?

Have this code Po155 oxy sensor heated bank 2 sen 1. I have replaced all sensor in the tail pips and check engine light code still comes on.

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Ford F-150 - 1997-2003 :: 1999 XLT 5.4L - Getting P0171 Code Only?

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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Ford F-150 - 1997-2003 :: 2000 V6 - CEL On / Code Reader Won't Come On

2000 F150 V6 auto just bought it 140k. Check engine light on.. Code reader wont come on? has 2 lighter sockets in dash one on the left works right one dont? I hear one is inline with the code port? Checked 1 fuse #110? looked good...I don't have a manual so I"m lost.. or there are more fuses?

Also the speedo mileage sometimes will go blank? at start up then come back on ?? seems to be working even when blank? First I need to get the code reader port to put out..so i can see the codes....

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Ford F-150 - 1997-2003 :: PCM Keeps Giving OBD Code P0351

OK as you most know I have been having trouble with a Misfire on my truck. The PCM keeps giving me a OBD code of P0351. I have driven the truck the last few days with out running the AC and I have no problem with the truck. It runs great. When I turn on AC about 20 minutes into driving my truck starts misfiring and I get the p0351. Was wondering why the Running the AC would cause this?

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Ford F-150 - 1997-2003 :: P0401 Code - Vacuum Lines?

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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Ford F-150 - 1997-2003 :: Code P0172 / Bank One Is Too Rich

So my truck is reading a code at P0172 which means bank one is too rich. I replaced all of my o2 sensors, cleaned my MAF, and replaced PCV and hoses connected to it. What else could it be?

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Ford F-150 - 1997-2003 :: 1998 - Code 402 And Oil Pressure Drops

I've got a '98 F150.throwing codd 402, excessive flow EGR, also the oil pressure drops to absolute zero only when gear shifts but comes right back up. No knocking or other distress sounds in engine. I know I'm in need of an oil change. I already searched a bit and decided to swap out the DPFE sensor which I did purchase from the dealership. No code as of yet but what could that pressure drop be? Could a simple il change and filter fix that?

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Ford F-150 - 1997-2003 :: Code P0306 - Cylinder 6 Misfire

So my 99 F-150, 4.2L started throwing a code a few weeks ago, P0306 #6 Cyl Misfire. This thing has got 238,000 and has been the most reliable commute vehicle I've owned.

Today I changed all the plugs and wires (they were due anyways) which didn't resolve the issue. After clearing the code, got about 3 miles out and it came back. Running SeaFoam through the system on this tank as well, but I'm leaning towards an EGR blockage like what is described here:

Sparky's Answers: 1999 Ford F150, P0306 Misfire Cylinder #6

I was about to buy a new coil pack but I'd rather not continue to throw parts at this, as I've read many others do with this same exact situation, only to end up with the same code. I've replaced the coil pack once already a few years ago when I lost a cylinder on the way to work.

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Ford F-150 - 1997-2003 :: CEL Code P0301 / Misfire With Cylinder 1

My 97 F150 through a CEL Tuesday night P0301 so I picked up a new plug because it's cheap and simple, but that didn't do anything. Spark plug wires are about 3 months old, I also swapped injectors between 1 and 2, and misfire stayed with cylinder 1. It also gained a tap when the misfire started but only above idle, but it doesn't sound like a rod knock.

I also noticed if you unplug injector 1at idle it taps/knocks 3 or 4 times, however if you unplug any of the others it doesn't do that. I checked and I definitely have good spark from the plug. I plan on picking up a new compression tester tomorrow since mine never was returned. If you take the oil fill cap off it doesn't have any blow by at idle, however if you rev it you get a quick cloud out of it.

I thought about picking up a kit to check the injector pulse.

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Ford F-150 - 1997-2003 :: Code P0171 - Fuel Pressure?

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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Ford F-150 - 1997-2003 :: Getting Code P1299 With Plenty Of Coolant

I'm getting a p1299 code..it has plenty of coolant in it..what's the next step I should do to address the problem?

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