hey all! new to the forum. I'm having trouble with my lb7 duramax. I was having problems with my tranny a couple months ago. it would shift all the way to third but wouldn't go past. I did some research and came to the conclusion that I needed to replace my neutral safety switch. So that's what I did, but after I replaced it, I turned the truck on and it said it was in drive (supposed to be neutral) on the dash. It shifted fine in drive for awhile but I couldn't manually put it in 1st. after a couple weeks it went back to only shifting to third. I figured I put it in wrong since it said it was in drive when I turned the truck on. so I changed it again but this time, triple checked everything. did the same thing when I turned it on. now its stuck in fourth gear, wont upshift or downshift. I have efi live, was just wondering if maybe I needed to reprogram my computer? anyways, any help would be appreciated. what do you guys think?