Last year was a pretty light winter, but when it did snow I had an issue with rough idle, and stuttering while accelerating. It only happened the 2 days it was really cold and then it went away. I thought it might have been condensation in the tank from the freezing.

This past week, this year's snow came and so did the problem.

Starts fine, and runs fine for about 15 mins. Then it starts to get rough.

Runs rough at a stop while in Drive, but smooths out if stopped and I put it in neutral.

Stutters at acceleration from a stop and then seems to smooth out as driving, but if I take my foot off the accelerator and then give it gas it stutters again.

Freeway driving is hit and miss. It will smooth out over 65. Between 50-65 it is rough when applying the acclerator.

Service engine light will sometimes flash when this happening.

I have searched and found info on everything from Rear 02 sensor, to IAC, to coils. Was hoping someone here can provide some insight so I don't throw money at it for parts that are not needed.

2001 Supercrew Lariat, 5.4 V8, 4x4, just over 80k. Would like to fix it myself.

 

Just a guess but when is the last time you changed the fuel filter?
The cold weather could be causing condensation/water to freeze in the filter thus causing a starvation effect at idle. More fuel and less problems at higher speeds.
Just a thought.

 

I would run a code check on it and also run one for the pending codes. That may give you a idea of whats going on. And if it been a while since a filter change that would be a good idea.

 

a flashing cel means missfire... how old are plugs and wires... also if the fuel filter hasnt been changed in awhile i would also check that