I have an 01 5.4 4x4 supercrew, I don't drive the truck much anymore but lately I've noticed that if I'm driving around 50 mph in overdrive and torque coverter is locked, if I let off the gas and coast down to about 40mph or so and barely get back on the gas, I feel the truck bucking. If I mash on it, it will clear up. It feels like a misfire but my 30+ years of being an import tech leads me to think its torque converter shutter. I had changed the fluid about 8 months ago but only maybe a 1000 miles. I'm about to change the spark plugs out now because I know they have been in there since I bought it, about 60,000 miles ago. Sometimes when I start it cold it will mis until I gas it a time
or two, so maybe it's a misfire. Two problems starting at the same time? I guess it can happen. Anyway I was wondering if any of you fellas recommend a good additive to maybe help with shutter? Can't hurt anything to try.

 

Odds are good it's a low grade misfire. See if you can find someone with a mid range scanner that can read mode $06.

Or buy a new cop, and start swapping it out one cylinder at a time. Or replace them all.

 

Well it finally set a code p0302. Change out the #2 coil pack and plug and its all good. I still need to change out the rest of the plugs. Got 1 and two the my socket slipped on the #3 coil retaining bolt. These aren't the worst plugs I've changed but they're close. I brought it to work tonight where I have more tools.

 

Yea, swivels come in handy for these. Thanks for the update.