Unfortunately Cosworth, that would not be correct. It takes the S2000 ECU at least 5 'drives' (3-4 days) to register any changes in the system, per the manual. Case in point, read the page of your manual that talks about the Check Engine Light.

 

Keith - I wouldn't be able to check the manual... I don't own a S2000.

 

Then what are you doing here?? Go away!! Just kidding.

But it is true. For certain environmental changes the ECU will re-sample the given stimuli for 4-5 days before adjusting itself. To get change quicker would require a reset. The infamous 'gas cap sensor'(which I think is ALL KINDS OF STUPID) is a great example.