Going to have a p59 over the weekend will do the same steps as you and will report back

What software are you using to tune the .bin file?

Yes, you update the OS with a bin file similar to what you have (example 2001 ls1 with 4l60e), first flash the stock .bin with the OS you want, then start making the changes you want

Thanks for the help.

Would I be able to save my .bin file and revert back to the 9381344 OS and the "safe tune" if I needed?[/QUOTE]

Yes, you can save your .bin file and back it up if you need...

Yes that is correct, you'll have to tune the pcm

You'll need to update your OS, i flashed another bin to my pcm and then i was able to tune my pcm

No, i updated my pcm to an OS with an available xdf file and now all is working fine

Hi i'm new here, first of all thanks LRT for the great work, second does anyone has a 9381344 OS XDF File? I've find only one for a F body and i'm not sure it'll work in my 4.8 out of a 2000...