I'm not an expert, but what I know is that you can't change the way the sensor detects the air mixture. Had the same problem with the 355 after installing the tubi stuff.

However, that's not a serious problem. The dealer told me that I don't have to worry. Due to the changed mixture (which is nevertheless better than before) the sensor will come on sometimes. Maybe Manu from Scuderiasystems can tell you more about it...or check www.ferrarichat.com. There you'll find answers.