I have the A2a 172 and in level flight, with the perfectly clear weather checked, it pulls to the left in a strong manner. Setting the P-factor and Torque slider to any setting does not seem to make any difference. I have watched the raw values from my rudder pedals and yoke and they are not any different during flight than with any other aircraft. Re-calibrated several times with built-in calibration and CH Products calibration. ????

 

I can fly the A2A Cub straight and level ok in locked "perfect" weather.

Fuel (fool)  The fule is not replenished automatically. After trying to load fuel via the usual Payload screen it became obvious I needed to check the manual. After that embarrassment, I learned how to load fuel and details how the tanks become unbalanced. No wonder the pane flew straight on the first flight. It just became progressive ly worse falling to the left the more I used it. 

 

After years of "flying" vanilla aircraft this one impresses you with the real complexity of the here-to-fore simple Cessna 172.

Take it in to the hangar and see if your flight controls need repairs.

nudata, please don't EVER have second thoughts about using X-Plane 10... You'll get sick... Roll due to torque is soooo overdone in that sim, whenever you're flying a prop aircraft ( something that most fsx aircraft also have, instead of yaw... ) that sometimes it's really distracting from other good points that sim does have ...