Problems with EGR valve

[Dalrymple]

I recently changed out the EGR valve on my ram 1500 because of the hissing noise it was making as well as the lack of power, I couldn't get it past 35. After I changed it out I still had the lack of power and the hissing noise started up again when the hose came off of the back pressure fitting. I need help on trying to figure out what is causing this.

 

[ramtruckdriver]

Most likely the cat/conv is restricting the exhaust, Also possibly if puff of smoke on startup, the valves seals have unseated because of exhaust back pressure

 

[Dalrymple]

After doing some more research the next thing I was going to check was the catalytic converters, but luckily there is no puff of smoke during startup that I have seen