Have you ever heard of fuel injector problems? My truck kind of idles a little rougher than it should. I have a 2005 F-150XLT 5.4 v8 with a sct chip, with 33,000 miles on it. I took it to FORD and they tried saying it was because I have an aftermarket exhaust(which I know is a bunch of BS). It doesnt idle rough all the time. Kind of off and on. My bumper to bumper warranty is good until 75,000 miles and the only thing that ford automatically extends is the fuel injectors which makes me a little suspicious... Ever hear of this problem? Thanks...