I have a 99 RK that is pushing air back through the intake on the back bank. It has gradually gotten worse. I am not sure of what EFI system that it has. One HD dealer says its a head gasket and another says its not. At this point I am at a loss. Any help here would appreciated. Thanks

 

Sounds like a bad intake valve on the rear cylinder. A simple "leakdown" test would put you right on it, whatever it is.

 

Update, it is sparking in the back bank if the intake. This is really pissing me off.