He sat in the driver's seat, laptop balanced on his knees, and plugged his OBD2 adapter into the dash. He opened the FORScan software but quickly hit a roadblock: to change the tire size, he needed an .
This is a popular option for DIYers performing a one-time modification. It requires a registered account on the FORScan forums and is valid for two months. It can be renewed, but it is intended for non-commercial use. forscan license key