Exhaust back pressure valve

[95-2Fiddy]

Hello there i am fairly new to diesels and i was reading in the new to 7.3 post that a huge power loss and hissing sound is the ebpv closing. My truck never did this before and i lifted the motor up to change my oil pan (yes it leaks worse than it did before so next week comes the project of pulling the motor and doing it right) but when i ran it after i got everything back together it had exactly that, absolutely no power and a hissing sound. i havent ran it that long with the re-found leak but i was just wondering where the ebpv valve was and if it can be pulled right out if nothing else just to see if thats whats doing it or why it would start doing this all of a sudden. I want to figure out why its running like this so i can get it back to the way it was because im thinking about getting injectors a couple things while the motor is out so im not leaning over a fender to do it since its going to be out anyways, or is there a wire that could have been pulled ( i checked everything but cant say i didnt miss something. i just want to know everything was normall before i pull the motor so if there would happen to be some other problem and be more of a headache knowing it didnt run right before i started. Thanks for any help in advance