I have 17 RT. I get a loud knock from engine upon startup for a couple seconds. It only does it in an incline such as driveway no mater if I park nose first or reverse. It doesn’t do it all the time. Has anyone else had this issue? Lifter? Valve? Going to take it to dealership on Saturday. Only mods are shortys, mopar cai, catch can, 3G halfcovers and metco breather.