I bought my truck a few months ago and everything was fine, then it started having this low/no power when cold issue.

I was trying to remember when I started having this problem, I think it started after I changed the OIL and filter. Do you think the dealer could have put some sort of additive or maybe it could of had 5W40 oil in it, I put 15w40 motorcraft back in with the motorcraft filter?

Could this be caused by a bad injector?