Ok, i just purchased a 2003 Dodge Ram, 4.7L, Airaid Cold Air Inatake, Single Flowmaster.. already installed on it. When the truck gets at average temp. it starts to make a knocking sound kinda like the exhaust is hitting the frame... i checked the exhuast and its secured.... when it is in drive it gets louder... it is very annoying... what is it? oh yea its an automatic..