I want to bring attention to the Q&A section in Bike India January 2009 edition. The first question is asked by someone wanting to fit a K&N airfilter to his R15. He was concerned if the bike would need re-jetting since it is fuel injected.
Bike India's response:- Yes, you can fit a K&N filter on the R15. The ECU of a fuel injection system will automatically alter the fuel flow to suit the free flow filter.
The above answer is INCORRECT. The R15 fuel injection system will NOT adjust the fuel flow automatically because it runs an open loop fuel injection system. There is no O2 sensor providing feedback to the ECU on whether the bike is running rich or lean. On the R15, the airfuel ratio needs to be set manually with a handheld controller available for the purpose. Open loop FI systems are used on small bikes like the r15 to save costs. There are also closed loop FI systems such as those used in cars and they are quite expensive. A closed loop system is capable of making adjustments to the fuel flow based on inputs from various sensors in the vehicle.
Magazines should be 100% sure before publishing such info to the masses. If anyone here can convey this to the right people in Bike India, please do.