Yeah, Lund was really good communicating with me, but they cannot give me a revision for the stock tune. I think I will take it to the Ford dealer like you said. Hopefully they are open during the apocalypse.
Thanks for your input. I am currently having this issue on my 2013 GT. I am selling the car in CA and the car is state reffed (from the previous owner; sigh) so I was forced to put the stock headers, cats, and H pipe back on. I had a 91-93 Lund tune on it with the longtubes and xpipe, but I...