I went throught the BEN factor mappings until I reached 1s, then followed the steps for creating the Closed Loop SD tune. Flashed the tune into the truck and I'm getting -10 and -12 ltfts on exceleration and 2 and 4 ltfts on a constant cruise at 2000 rpms. I'm using the driver side ltft for monitoring purposes since I suspect a leak on the passenger side exhaust.
Engine temp was 183 F degrees during the -12 ltft occurence.

Why am I getting such large rich values and lean values this high? I'm positive that during the scan I did hit the cells which were producing these rich ltfts.

The tune was flashed this morning and the erratic LTFTs were noticed this afternoon after less than 75 miles of driving.

Do I need to give more time for the PCM to learn?