I have a 2006 Kenworth with a Cat engine. The radio is wired directly to the battery. I have ran several grounds in various places, moved the antenna to no avail. The RFI is coming from the wiring harness that goes from the ECM to the fuel injectors. I used a sniffer to find this out. The noise is a popping noise that is directly related to the amount of fuel applied. I have tried some ferrites on the injector wires under the rocker covers, but didn't help. When no fuel is applied there is no noise. There is no electric fuel pump. WHAT DO I DO? I'm gonna go insane listening to this crap :x :x :x :x