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.

View 14 Replies

Ford F-150 (2004-2008) :: Power Loss / Check Engine Light / Misfire On Cylinder 5 And 6

I have a 2008 FX2 5.4L F150. Recently it began to lose power on a friend driving it out of town. He got a check engine light then it just progressively became unable to produce power. It ran but he got down to 10 mph before he could get to a firestone. I got it to a local Ford dealer and they say i need a new engine. They gave me codes for cam sensor and timing and #5 and #6 misfire. (344, 345)

No oil in radiator, no water in oil. The crazy thing is it runs like the day i bought it in Park. But once in gear it begins to cough and then eventually shudders and dies. I haven't changed plugs ever. I know... At about 75 miles it began to idle rough at times and in reverse. But once I revved up it went away.

I replaced both cam sensors but no luck. Today i put it on a tow truck to get a second opinion from a local engine shop. I actually backed it down my driveway, and pulled up to the tow truck with no issues. weird...

View 2 Replies

Santa FE SM (2001-06) :: Code P0306 Came Up - Cylinder 6 Misfire

I have a 2004 Santa Fe with the 3.5. Today I started it and the check engine light came on. It was not on before this. (We had a lot of wind and rain from the storm but nothing major.) And seems to be running fine. I went to the auto parts store and they ran a diagnostic and the Code P0306 came up #6 cylinder misfire. They said probably Spark plug, wire or coil for #6, then went to look up code in computer and did not have my truck so they went with Kia or Domestic, which gave different possibilities for a code P0306.

They had me buy some fuel injector cleaner as injector was on the list. The light is still on so I guess the cleaner was not the magic bullet. I spoke to a lady at another auto parts store who is a wiz when it comes to cars and has been around them and fixing them a really long time. She says the Code P0306 is Spark Plug, wire, coil #6. She has a 4cyl Hyundai car not truck and she had the code for her #4 misfire in the past and she started her repair cheapest first, Plugs, wires her code was still there she then changed the coil and that did the trick for her.

I on the other hand can't do this stuff myself. Can't afford the dealer anymore or to have a shop do a tune up AND coil if I don't need all new plugs and wires just a coil as they will charge a lot to do a lot all. And it may not need it or even be any of those things. I also suspect the dealer and shops will want to still hook up their computers to do an costly diagnostic because the light is on, even though I know the parts store already came up with a code P0306 twice. Spoke to the dealer on the phone and he already basically said they would want to do that first for $100 plus the cost of repair.

I brought the truck new. It now has 91,500 miles on it and the dealer has already done two tuneups on it in that time, Plugs and wires. I hear it probably shouldn't have even needed these tuneups in this amount of millage? So the last one was probably about 2 years ago and a few thousand miles maybe a guess 10,000-20,000 miles ago. Do you think a plug and wire would be bad already in that few miles?

View 11 Replies

Town Car :: 1999 - OBDII Code Is P0306 Cylinder 6 Misfire

I have a 99 town car with 78,000 miles. I filled the tank and have run about 1/4 tank when the engine started to misfire. Got the Service Engine Soon light so went to O'reily. The OBDII code is p0306 cyl 6 misfire. What would you check first?

View 3 Replies

Buick - Regal :: 1996 - CEL Code P0306 Cylinder 6 Misfire Plus P0102 Mass Airflow Sensor

Ok, my 1996 Buick Regal is acting up. I got a CEL, which was a P0306 (Cylinder #6 misfire), took the car to my shop, and they diagnosed as a faulty Ignition Control Module. Fast Forward, a day later, the car now has a hard start problem and throwing the same code, plus a P0102 Mass Airflow Sensor.

So my questions are:

1) Could a faulty ICM cause a single cylinder misfire, did they just replaced a random part? I would think a bad ICM would a multiple misfire considering on this car each coil controls 2 cylinders.
2) Are the two codes related? ie fix one, and the other would go away? or are they separate issues?
3) What could be wrong with my car?

This mechanic has been in my family for years, however, I'm not very pleased that a day later, my car seems to have more problems than before. Am I being too harsh?

View 19 Replies

Civic - Honda :: Cylinder 2 Misfire Code As Well As Random Power Loss

I had plugs and wires changed to try clear code. Car seemed to do some better but while trying to go up a steep hill car started stuttering and jerking. Power went out of car and check engine light started blinking fast. After let the car sit for bout 45mins car started running fine again and light stopped flashing but remained on. Code read cylinder2 misfire again.

View 1 Replies

Golf IV / Jetta IV :: Loss Of Power And Hesitation / CEL Code For Misfire On Cylinder 1 And 5

When i got my 2000 jetta vr6 it has a CEL for misfires. Searched this board and google already. Im thinking injectors (havent checked yet) I noticed something weird the other day. At a light i get the CEL flashing. Then after a bit it will come on and stay on. I plugged in my generic reader and deleted the codes. When the CEL is on I get loss of power and hesitation. When its deleted the car runs better. I get my power back. I looked in the coolant tank and see no bubbles. Could this be the ECM? Im still going to get injectors but want to buy the gasket and anything else I am going to need to put it back together. I already cleaned the MAF, replaced some vac lines, coil pack, wires and checked plugs (gapped at .28) ...

View 4 Replies

Subaru - Legacy :: 1999 - Cylinder 2 Misfire Code As Well As Random Power Loss

I had plugs and wires changed to try clear code. Car seemed to do some better but while trying to go up a steep hill car started stuttering and jerking. Power went out of car and check engine light started blinking fast.after let the car sit for bout 45mins car started running fine again and light stopped flashing but remained on. Code read cylinder2 misfire again.

View 10 Replies

Ford F-150 (2004-2008) :: 2007 - Cylinder 3 Misfire Code

I know there is a tun of info on the spark plug problem on the f-150. Here is the problem I have and I don't know where else to look.

Cylinder #3 misfires

1. swapped coil with #2 cylinder and still throws #3 misfire code.
2. Changed the plug on #3 and still the same code #3 misfire.

Where to look next?

View 13 Replies

Ford F-150 (2004-2008) :: Code P0301 - Misfire Cylinder 1

This happened xmas shopping with the wife. Started misfiring on the highway,took the 1st exit to find a garage as I am 20kms from home. The vibrations were worse at stop, but made it to a garage. They gave me the p0301 misfire cylinder 1, said they don't touch 5.4 plugs, told me to go to ford 2kms down the road. NICE. 4 in the pm, FORD dealer worse case scenario. Nope gave me a loaner told me come back at 930am. Truck was just waiting for an injector when I arrived. Plug & coil were good injector was shot,changed the fuel filter & oil change.

View 6 Replies

Ford F-150 (2004-2008) :: Cylinder 8 Misfire Code Randomly

Having a misfire problem I can't track down. First issue was random cylinder 8 misfire code. Checked everything, nothing obvious. Cleared code, problem stopped and engine ran fine. Then came back, cylinder 8 misfire. Swapped coil with #5 but problem did not return. Since I assumed it would come back, I went ahead and bought Accell supercoils and new Motorcraft plugs and replaced them all (120k miles, no broken plugs ). Truck ran great on the test drive! Then it sits overnight and bam, cylinder 5 misfire as soon as I start it next morning. Then after messing with it I get cylinder 5 bad coil (code 355 I think). Put one of the Ford factory coils back back on #5, no change and still misfiring. New plug, new coil on all cylinders... Why did it move from #8 to #5? If it was an in injector, seems it would still be #8 since I did not mess with those.

View 10 Replies

Ford F-150 (2004-2008) :: Code PO306 Which Is Misfire On Cylinder 6

I have a 2004 f150 with the 5.4 and was wondering what would cause a spark plug to do this. Its on cylinder 6 and i have pulled the codes off of the truck before and one was PO306 which is misfire and can't remember other one but it was saying system was too rich. I have only has this spark plug in maybe 500 miles. but was getting a misfire code before that. Do you think it could be a coil or the injector?

View 3 Replies

Ford F-150 (2004-2008) :: Code P0308 Read Out Misfire On Cylinder 8

Started as I was warming up the truck,a slight vibration/shudder. First thing that came to mind was F150. Torqued words of wisdom that it might come back, I had a p0301 before. Had no CEL, so decided to drive it to see if it got worse. Turned onto the main road and on came the CEL. Pulled into my FORD dealer, told him about my problem. Code P0308 misfire on #8cylinder was the read out, COP was done and the plug. 40 min of labor. She's even quieter than when #1 got changed.

View 3 Replies

Ford F-150 (2004-2008) :: 2006 - Misfire On Cylinder 1 / Code P0301

I have a 2006 F150 with a cylinder #1 misfire only code p0301. I have done new spark plugs, new coil packs, and new fuel injector on cylinder #1 with no luck. What to do next?

View 5 Replies

Ford F-150 (2004-2008) :: E250 - Code PO306 Misfire On Cylinder 6

I have a 08 E250 4.6 getting code po306 misfire #6.. What should I check or change first and where is # 6 looking from the front of truck looking at the seats the driver's seat on my right # 1 is where and #6 is where oh 57,342 miles...

View 4 Replies

Ford F-150 (2004-2008) :: 2005 - Misfire Badly - Power Loss?

i have a 2005 expedition with the 5.4 and 100k miles. Rescently it began to missfire badly and lost almost all power to the point where it nearly dies. I have seveal codes that are baffeling me. Bank 1 is rich bank 2 is lean(this may be the other way around, p0300(multiple cyl missfire) and then 4 individual cyl missfire codes. I changed all of the spark plugs with factory motocraft ones from ford as the old ones were shot. Seems to miss just as badly as before and is no where near driveable. What would cause one bank to be rich and one bank lean? I ohmed all of the coils when I had them out and they all are very close to each other with no odd ball ohm readings so I believe they are all ok. Any sugestions as to where to check next?

View 3 Replies

Ford F-150 (2004-2008) :: Rough Idle And Hard Miss Under Load - CEL Code P0306

2005 f150 5.4.

I have a slightly rough idle and can feel a miss at 1600 to 2000 RPM. Sometimes running about 65 MPH up a slight grade I can slowly press the gas pedal and the engine will begin to miss much worse, causing the truck to shake pretty bad. When it gets this bad it will slowly flash the CEL and I get a P0306 code (Cyl 6 missfire).

The truck has 148000 Miles on it and the plugs were replaced at approx 120000 by the dealer.

In the last week I have replaced the plug in cylinder 6 (looked ok) and have replaced all the COP's along with the fuel filter and the injector on #6.

I haven't been able to get it flash the CEL light or throw a code since replacing the COPs though and I am at a loss at to what to try next.

View 2 Replies

Ford Escape / Hybrid :: 2002 - Misfire - Getting Code P0305 And P0306?

I have a very Big problem with my Ford Escape 2002 I have this problems code: P0305 accuses Cylinder #5 P0306 accuses Cylinder #6.

I already change the gasket i buy the felpro Kit, and i Also replace all the sparks and spark plug boots, I clean the air sensors and i also replace the EGR, i try to switch cables, and all is the same the car start buy when i accelerate it just go off, i don't know what can i do next, somebody told me to change the fuel injector, i take the pressure in both spark holes the number 4 was 150 and the 5 and 6 was 120, No leaks oil. My car is a Ford Escape 2002, XLT 3.0 4x4

View 2 Replies

Ford 6.0L Power Stroke Diesel :: Loss Of Power / Codes For Low Voltage / FICM And Cylinder 6 Misfire

Well, coming home from work Friday and my truck turned on the check engine light. I did not notice any loss of power or other driveability issues. When I got home I pulled the DTC's. I got P0264, P0273, P0276, P0279, P0611, and U0306. The first four being low voltages. The Second FICM. And the last cylinder 6 misfire.

I sent a message to Ed at FICM Repair asking if there was anything to check before I pulled the beast. He said no it needed service no matter what at this point. BUT, I needed to test batteries and alternator. So I spent some time today pulling off my FICM.

I went ahead and pulled the EBP sensor and tube off from the exhaust manifold. The manifold end was very clean. BUT, the sensor end had a noticeable restriction. I would guess a 40% restriction. I cleaned the tube and the sensor and put it back on.

Next I moved to the EGR. I pulled it off and it was dirty but not what I would call restricted. The valve moved freely. I cleaned it anyway and blew out the manifold before I reinstalled it.

I have the batteries on a charger right now. Once they each charge for 12 hours each I will let them sit a day or two before I load test them. They are about four years old, AC Delco 60 month 875CCA batteries. I have had problems the last 6-8 months with staring the truck. If she sits for more than 3-4 weeks without being run she turns over slow and won't start. So I have had to jump start her a few times. And before you ask I have done a parasitic check and only have .05amp draw. So maybe the alternator is getting weak.

On that note I pulled the alternator and will get it bench tested this week. While I was there I noticed the top grooved and smooth idler pullies were a little "wobbly" so I yanked them too and will replace. Might as well do the belt while I'm at it. Boy this is going to get expensive real fast.

So, I decided to go ahead and replace the bottom coolant recovery hose and the long hose/pipe heater hose too. Boy it never ends. Oh well. I would rather do it now while I have stuff pulled off and it is easier to get to. Ordered those parts from RockAuto to the tune of 219 dollars. OUCH!!!

I accidentally broke my new engine oil dipstick while I was trying to get to the FICM!!!! CRAP!!!! More money. So......... Is there anything else I might want to look at while I am there?

The truck is 2006 F250 6.0 PSD CC SB 4x4 mid optioned XLT with 108,000+ miles. I have a 4" turbo back exhaust, AFE Cold Air Intake, Blue Spring, Hypertec Power Program 3 on the lowest setting, and an after market intake elbow at the intake manifold and an engine oil bypass filter. Turbo was pulled and de-coked about 18,000 miles back. Otherwise no issues. The 90,000 mile service was done about 10,000 miles ago. She gets regular services.

How about methanol injection? Will that keep the intake clean from the EGR sludge? I'm not thinking about added power, just keeping things cleaner? I plan to do the Atlas 40 when the FICM gets repaired.

View 14 Replies