solution was pretty simple & I wasn't even trying to correct this

for years the a/c in my truck (01) stunk to hell and the stuff the dealer's and a/c service people love to spray in the system gave me headaches

the fall before last , I bought and installed a street scene smooth cowel top and low & behold the following summer the stink from the a/c was almost gone
I used the a/c yesterday & I'm happy to say it didn't stink at all

one thing though
now that the truck breathes through the body I do have to turn the heat or a/c off while behind another car while waiteing at a drive through as it sucks the exhaust stink from the car ahead of me into the cab
but that's easy to deal with , I just turn the heater or a/c off