Ok I didn't like the reception using the usb fm I had, so I put back me head unit. The HU is a pioneer I had in the car before I put the carputer in and it had great reception. Now it gets just as bad reception that I was getting with the usb tuner. Why is that and is there anything I can do about it?
Antenna location, your connection from the HU to the antenna, where was your car parked when you did the tests?
Have you tried disconnecting any aftermarket devices that you installed after the reception problems? switching power supplies are notorious for making radio suck...
Check your grounding and all your other wiring as well, and try disconnecting EVERYTHING but the radio and make sure you're draining your battery and not running off an alternator, if that doesn't fix the problem, call god and tell him to make your radio not suck..