This is gunna be a story, so get ready!
So today, I went and met a guy who was selling a SCT livewire for $200. WE meet up and we plug the cable into the OBD port under the dash and it won't work. The gentleman was an older fellow who recently sold his 6.0 so he had no need for the chip, so he gave it to me for free


and said I hope I can get it working.
I go home and load the SCT onto our old farm truck (04 6.0) and it loads up fine. We have had this truck since new so I know there is no sort of chip or tuning already on the motor.
What I"m getting at is how can I tell if my truck already has a chip or somesort of tuning on it. I bought it used, so I don't know much of the previous owner. After a couple hours from driving it home, I noticed that there was some black smoke on the back fender where the exhaust came out.
Is there anyway to "reflash" my ECM so that I can load up my free SCT??? Or how do I check if there is a chip or something else on it?