There was a problem identified in the custom O.S#3 for all 2003+ vehicles that was causing the ECT enrichment table to have no effect on final commanded AFR's when cold. This has been fixed and the updated .tun files are available by downoading the zip file shown below.

1 - Download zip file.
2 - Extract into the folder you store your tune files.
3 - Choose the custom O.S to match your exisiting tune (these new ones have a 'c' at the end of the file name).
4 - Full flash PCM.
5 - Calibration only flash the PCM with your existing calibrations.
6 - Alter ECT fuel table as required.

Updated Custom OS file link (5.05Mb) - CLICK HERE

Cheers,
Ross