I have this mod and from what I am told it is the reason my CB doesnt pick up squat but the sound of the engine RPM like a gas with bad spark plug wires and grounds.
trust me the IDM isnt the reason for the noise in the CB.some people have experienced noises in thier CB caused by fords electric fuel pumps.i noticed you have a 99,that has 2 electric pumps on it.check out www.cbradiotalk.com for tons of info.my user name there is grease monkey.