Needing some Advise
 

so as yall know i got a 04 2500, and last week i noticed my exhaust sounding differnt. So i got my wife to drive my truck and i drove beside it and it had a sound as almost it had an injector out. So I took it to my bro-in-law shop we hooked the computer up to it and everything was fine. No Codes and all the injectors were firing fine. So i changed my fuel filter (which wasnt that dirty) and tried it again. Same sound. Now i did notice you can hear it alot more when towing and just barely when not. So does anyone have any suggestions on what to look at?

Also, when i first start my truck my tranny doesnt seem to have line pressure until i give it some throttle and then it seems slow to engage, almost like letting out on the clutch.

The truck still runs great and pulls my car trailer with the mud truck on it great, i just dont want to ignore it and then it blows up on me going down the road. Thanks for any info.