About two years ago I purchased and installed a K & N filter injection performance kit for my 97 Ranger 4x4 with the 4.0V6. About three months ago I started to hear a loud noise at cruising speed that would change in tone when I would lightly tap on the gas and would go away for a short while when I would stomp on the peddle. A couple of sources told me that the idle air control needed to be cleaned. Has any one heard of this happening? How hard is this to disassemble and clean? what type of fluid is needed to clean this part? Thank you for your time.