Hello,
purchased a 2015, 1500 5.3 a few weeks ago and last night on a very quiet road as i was accelerating i could hear a click/rattle in the exhaust. After driving it a little bit more today with the radio down and AC off i can definitely hear it more. It doesn’t really do it when i have the cruise set but as soon as i touch the throttle to accelerate i can hear it start. I’ve done some reading and some people say it’s the Flap valve in the exhaust but I’m not sure. AFM is disabled via a programmer. Any thoughts?