Egr valve

[4MiraclesT]

So i have had a low power issue for quite some time now no codes no derates just sluggish. I was just dealing with it as after several trips to different shops no one could tell me anything other than “ try changing your fuel filters” but about 2 months ago it started getting more and more noticeable and I’ve lost almost a mpg. I’ve done the egr tune up, and adjusted the overhead. While removing the egr cross over tube to check under the valvecover last week, i cold started the truck and noticed i had egr flow at any throttle position. Its my understanding that this should not be. Also my dpf has been sooting up much mor rapidly. As a test i turned key on let the egr valve go closed then disconnected the plug and drove for about 100 mi, response seemed better aside from the derate however my dpf cleaned itself out and stayed that way till i hooked the valve back up then went back to sooting up again. My very long winded question is Are there any tests i can do without insite as i dont have access to it. I dont want to shoot the parts cannon pff as the valve os not cheap. Any help is appreciated
This is a 2013 cm2350