I have a 2004 F150 Supercrew Lariat. 5.4L v8 engine. 130k miles. 4x4. Runs great. Every now and then, when i decelerate and then accelerate slowly (rpm is very low, mph is between 45-65), I get a loud sound in the cab of the truck, until i accelerate quicker. It also feels like i lose power until i push the gas pedal in more. Could this be an exhaust leak? Any information would be greatly appreciated.