Two days ago I was driving down the highway and my blazer seemed to slip out of drive. The RPMs were bouncing and I seemed to have some power to keep me at about 55mph but it kept dropping so I pulled over. There was ATF all over the side of the truck and I saw that my upper transmission cooler line had come out because the clip was missing. I put fluid in it and rigged the line so it wouldnt come back out to get it home. Got my clip and put it all back together and filled it up but now it wont shift out of 2nd to 3rd. 1st 2nd and reverse all work just fine. So I tried unhooking the battery to reset it and get it out of limp mode but it still is doing the same thing. I'm looking for ideas on what could be causing this issue. It may still be in limp mode but it is not throwing any new codes. I have code p442 and p405 permanently from using a motor that didnt have egr hookups and my ABS light is on all the time but it has never effected anything. Any help would be greatly appreciated.

 

Also I've done some reading. Doesnt seem to be the VSS as my speedo works just fine. Its not stuck in 4wd and it goes just fine back and forth between 2w and 4w. It also has not shut down or anything on me yet. I'm not sure if it matters or not but the day previous to this all happening my wife had left it in 4w high for about 20 miles on the highway. Seemed to be working fine right up until the line came off however.