My F150 misses when I accellerate. The check engine light is on. I have a 4.6L extended cab 4x2. I just put in a Cold Air Intake, I don't know if this has anything to do with it. I did take it to AutoZone and they ran the OBD II and came back with a code of P0302 misfire on #2, they reset the check engine light and it was off, until this morning. Anybody else have this problem? What did you do.

Thanks

 

HOW MANY MILES DO YOU HAVE ON THE TRUCK? HAVE YOU CHANGED THE PLUGS AND WIRES? MINE DEVELOPED A MISS AT 100,000 MILES. CHANGED THE PLUGS AND WIRES AND SOLVED THE PROBLEM

 

I have about 74,000 mi on the truck. It only seems to miss during accelleration. If I'm up under the hood hitting the throttle it accellrates fine.

 

I just had the same problem with my Crown Victoria that has a 4.6L.
At 106K It started Skipping under load. I changed the spark plug wires and plugs. Fixed the problem. and alot more power.

 

Thanks Deebo

 

Well,

I have been having a similiar problem with my 5.4 with one exception.

Mine has a missfire all the time. The #7 Cylinder has had 6 coils replaced and each have failed within 1 minute to 1 month. I am told by my mechanic that they have had numerous coils go bad.

The missfire is probably a bad coil or plug wire.

 

I have a 97, with 40K miles on a replacement engine. I've owned it about 3 months now, and it also had a mis, which the dealer code showed plug wires. I replaced both the wires & the plugs, which improved it...for awhile. Then the mis turned into a stumble, then hard-running, like water in the gas. I tried gas-dryer, STP etc, no better, in fact, it was getting so bad, that I doubted I would make it home.

Well, after much digging, removing wire-plugs and seeing how it affects it, I think I found the problem. I removed the air-filter, only to find it was slightly torn, and a lame dome-shape plug is fitted into the inlet side of the filter. When the filter oblonged, it allowed the cone to rotate sideways, no longer filtering 100%. I removed the mass airflow assembly, found the elements were pretty dirty. I cleaned them with contact cleaner & WD40, and carefully dried with compressed air. I refitted a new filter and it now runs better than it ever has, since I've owned it. I hope this was the problem. I've heard of it happening with the Mustangs, so gave me the idea to look...I may have got lucky this time. Something to check...

 

I replaced the pllugs on my `97 F-150 4x4 4.6 when I had 100K on it.
That was 12k miles ago. I cleaned the engine about 3k miles1s ago and started having hesitation problems. Especially around 35-45 mph or going up a grade. Today it got real bad and fin7ally the dreaded CHECK ENGINE light appeared.
Took it to Advance Auto Parts about 15 minutes ago on the way home.
Ran fine to, slight hesitation, the hooked it up and find the same code you got PO302. Misfire on #2 cylinder.

Is it a coincidence or is this #2 misfire PO302 also related to the MAF sensor????

So I`m going to replace the wires, clean the MAF sensor and see what happens. BTW any good recomendations on where to buy the wires.
Dealer wants $100, NAPA wants $56.

 

This may help someone... I replace the plugs on my 97 4.6L at 40,000 before a long trip. About 10,000 miles later I noticed a hard stumble on heavy acceleration, like when I'm merging on the highway. No codes and she ran perfectly smooth otherwise. Changed the plugs and wires (pain in the A$$) and the problem went away for 6000 miles. Same stumble on hard accel. but no codes. Finally changed to autolite plats and no hesitation for 40,000 miles. The problem plugs were Bosch- never again. BTW the plugs looked perfect when I pulled them out, must have been misfiring under heavy load.

 

I have a 97 with a 4.6 in it. At about 70,000 it developed a miss. I got a tuneup and it seemed to run ok for about 10,000 then the miss started again. I replaced plug wires and the boots had holes blown in them. The new wires helped the horespower but the miss continues. Where is the mass air flow sensor at? It's got to either be that or one of the coils. I'll do the sensor first but am not sure where it is or what it looks like. HELP PLEASE.

 

My 97 F 150 4.6l had the same miss with about 50,000 on it. The check engine light was always on. After two trips to the Ford dealer they finnaly found were the spark was traveling outside of one of the sparkplugs. They replaced the plugs and 52,000 miles later it still runs like a top.

 

 

I have a `97 F-150 4X4 Off Road 4.6 Ext Cab
It now has 115,000, replaced plugs at 100,000.
Ran fine, then developed a miss when driving. Accelerated fine sitting.
AutoZone checked it...FREE of course....miss fire #2.
I replaced the plug wire.
Ran fine for a couple days then starting missing again.
Back to AutoZone, miss fire on #1.

I replaced ALL the plug wires, cost was $105.00 for OEM from the dealer. 2 weeks have gone by now and runs like a stripe-ed *** ape and shines like a diamond on a billy goats ***.

Next week I`ll replace the rear shoes for the first time.
Front pads were replaced at 90,000.

Its been a great running truck,dont know if I should keep it or get a new one. Dont know how long before something major goes, if it all.

 

Replace the plugs and wire's,Mine did the same thing,(had a bunch of mud in the engine foulling out a plug)

 

Ok, so now I'm under a new name because the site won't let me log in under my other name.

For those that posted that they have used seafoam, where did you get it and how do you use it?

Thanks,
TJ