u/FlyandPew

What am I doing wrong here. I have a 2018 5.0 Lariat Crewcab and just got new tires. I got Pirelli scorpion all terrain plus in 275/60/20. The speedometer was off, so I looked up how to set the mm in forscan. I found the 2570mm has me .5-1 mph faster than gps speed and that is good to me.

The problem is that I got the check engine light like everyone gets.

I reset the pcm adaptations, the transmission learned behavior, reset the abs module. Cleared the DTC’s…

The only way I can get the check engine light / DTC to clear is if I lower the mm size to like 2545 or set the hex code to a smaller size.

Why is 2570-2575 too big of a tire size?

What does everyone else do? There’s lifted trucks with big tires everywhere.