Funny thing, I bought my first FPR online for cheap (delphi), because the original was leaking; it was after that my truck started making noise. I thought because it was cheap, aftermarket, and the last thing i replaced that it was the cause; so i Sprung full retail at my local GM dealer for the oem part (ACDELCO). THE DELPHI AND THE ACDELCO FPR LOOK EXACTLY THE SAME. I installed the part and the noise persisted. It was a month or two later of living with this embarrassingly loud noise(28.F up here in Canada) that i replaced the fuel rails. immediately noticeable results (I could shake the fuel rails and hear a rattling inside).