Thereis a really good tuning guide on the forum under maintenance. That will show you how to set the fuel mix off the airbox. Definitely invest in a blue temp sender though. The mfa mpg reading isn't completely accurate but mine is close, 10mpg is awful. If your coolant levels are ok it's not an issue just annoying but a new sender should sort you out. Genuine parts are better but more expensive, get a genuine blue temp sender though. It is what the ecu uses to advance the ignition and for fuel.