Due to the volume of cars on a Dyno day they don't usually do an air/fuel ratio test/printout but they will to do it if specifically requested
prior to the day (ie tell me). The point they make is that for a A/F test, the car has to have been driven prior to the dyno to remove moisture(condensation) from the system. So if you are driving to the event there should be no issues. Naturally all cars will be warmed up prior to going onto the dyno.
As far as preparation is concerned, provided your car is driven on the road and serviced it should have no issues. They will do a pull in 3rd or 4th up to red line so any driveable car should be able to do that. Just make sure all your fluids are topped up.
Happy times!
Tree
Do we get A/F ratio print outs too? How should I prep the car (minimise any dramas, have heard stories, I'm just a paranoia fella lol)