The other week on my 2006 Tahoe Z71 I got in it to go to work and noticed it was way bogged down when taking off like it was in "limp" mode. I checked the transmission fluid and had to add 4oz short of 2 quarts to get the level back up in the checkerboard. Still drove the same after that. I had previously had a check engine light on for the week before due to the evap code. So I replaced the canister and valve to take care of the evap code. When I went to clear the evap code (assuming that was the only one still there from the last time I scanned it) I saw a bunch of transmission codes pop up particularly P0758. I took it in to one of the local transmission shops that did the rebuild of the transmission on my old '97 Tahoe about 8 years ago thinking they did good work and would be able to fix it for me. They scanned the codes and had pretty much every transmission code come up. They dropped the pan and checked what they could inside and that all looked good. They told me the transmission didn't have power to it and it was some type of electrical or connection issue that they couldn't fix. It seems to drive fine when I manually shift but when in "D" I try to take off from a stop and it's really bogged down and takes forever to get up to speed and then seems fine after. Almost like it is stuck in 3rd gear taking off or in "limp" mode or something. Looking for any help possible as this is my daily driver. Thanks.