ECU serial # 2C0-8591A-21
![qbaley69@gmail.com](https://ftecu.com/images/users/cWJhbGV5NjlAZ21haWwuY29t.jpg)
in R6
I have a 2007 R6 with the -21 ECU where FT only lists -20 and -31(CAN). The -21 superseded the -20 but I don't know what changed. Is there a problem with downloading a tune with -20 on a -21 ECU?