2007 Mercury Montego lurching

The check engine light is not on. I have almost 89,000 miles and my mechanic told at my last oil change a few weeks ago that the plugs, wires , filters and such were all fine. It only does it when the car is in drive and yes, it actually revs up regardless of whether your foot is on the brake or not. I read somewhere on the internet a few years ago that other Montego and Ford 500 owners have experienced the same issue, but no one could explain it or provide a fix. I have always wondered if it is a glitch in the onboard computer’s programming.