This is my first winter with my 4runner's. I'm still blaming the gas though because my wife V6 has suffered as well. I do however monitor both and will be keeping a close eye on them come May.
Is this your first winter with the truck?
I would suggest waiting until mid-May to give time for the winter blend gas to be out of circulation and see if your power//mpg's come back.
If they don't, then I'd look at other things- MAF sensor cleaning, maybe O2 sensor.
