Ripley's believe it or not.

Give us the name of your dealership and we'll all get our cars serviced there.

Do you hear like a whining noise coming from under the hood ! Just sayin'

Gster, I hadn't thought about them unhooking the battery, but that would recalibrate the computers and make the car act differently I would imagine.....I just don't know why they would have done that, and all stereo and other settings are unchanged, so they doesn't seem to fit. Maybe ford developed they're own Tornado for the intake system and this one really works! Moustang, how many miles were on your car when you did the oil change? Montreal Ponies, it was done at Capital Ford in Raleigh, NC. Pretty good dealership, but might not be worth the trip for you!

Just about anytime the dealership does work they unhook the battery. I think they use a code to keep radio channels. But this puts your computer back to factory settings. While your driving your computer learns your habits and drives a certain way.

This sounds like a plausible reason.

Could have been different road conditions? Some times I would be able to spin the tires in my 07 on a street and a different day I couldn't as much.