my truck has started to run weird higher rpms doesnt pull nearly as hard surges in reverse especially with a trailer connected rail pressure not meeting commanded amount, and doesnt smoke nearly as much egt are 400 if not 500 degrees lower then before!!!! changed my fass filters stock filters cant figure it out?!?!?! at times you can hear the fass pump surging but cant imagine that because you could even feel and power increase when installed !!!!!!!!!!!!!!please help