No effect for changes in a Pay type at the payroll

Dears,

Kindly, i have a pay type and whatever i make a changes on it like set the auto pay type method to "N" instead of "Y" or changing the fields of effect on gross/net pay the payroll is not affected by this changes although the pay is allowed for future entry and i deleted all history of this pay type from the time entry and i tried also to clear the cash, so can anyone help what may the cause of that and shall i do to let the payroll affected by this changes ?

Regards

Tamer ElSalahy