i drive a 2002 Ford F-150 Lariat 5.4L V8. My wife was backing out the drive way about a week or two ago, said that when she was backing out it felt like the truck was chugging. Later that evening I went to try it out, it in fact was chugging when in reverse but not going forward. I noticed it's a bit worse when tapping the brakes. It's been sitting in the driveway for about a week or two now. With my busy work schedule it's been hard to get under the truck late at night. Would make it easier if I had an idea of what to look for when I get the chance to work on it. Thanks.