low_and_slow_rainier

Okay tech guys it's question time. so like the title says I have a 2004 Buick Rainier with a 5.3 that was originally cammed with a tsp 224r awd with a 4l60, 3600 stall and 3.73 rear gears and ran pretty strong. I recently broke the 4l60 and a buddy of mine had a brand new 2wd Jake's 4l80e so I bought it and I also bought a 14 bolt with 4.10s out of a tbss. I also plan on eventually going turbo'd so I got a 3200 stall converter. I also bought a Jake's full manual controller so the original transmission harness is not hooked up at all. So I get everything installed and It now has a service awd light on and a CEL on and it feels like it has hardly any power in 1st gear. So my question is could the loss of power be related to the service awd light coming on because the computer thinks there's a problem so it's cutting engine power or would it be related to the tune. I'm running it on the same tune as the previous setup with 3600 stall and 3.73s. I would think that because the transmission has its own separate controller the stall and the gears wouldn't affect how the engine runs. I but I'm not sure hence why I'm here. I know the speedo needs to be fixed because of the rear gears and I need to scan the computer to find out what CEL is on for which I'll do tomorrow but didn't know if the service awd light could be why it feels so sluggish or if you think it's just the tune. Thanks in advance for any help you can give me.