You can not check piston rings by only removing the head. You also need to remove the pistons. Raw gasoline can not escape by the valve seals. Gasoline must first go through the valve seats and then exit through the exhaust system.
Possible causes of your problem:
* badly leaking fuel injectors
* Cold start valve always on due to defective temp. sensor or valve.
* Replace your air filter.
* Fuel regulator.
You said "the car runs great" That would indicate (altough not totally) that the rings are just fine and that there is no major bypass at the valve seats.
Check you fuel/vacuum system from a to Z first.
jackD