I have never had my hands on this "chip", but it is a part of the ECM (Electronic Control Module) which is the brain behind your EFI. The chip I am talking about is a set of calibration settings specifically designed to tell your brain (ECM) to operate the approximately 27 different EFI parameters in a way that matches up with what's on your motor. So anytime you change something significant---air cleaner, cam, bore, etc. --you need to rechip. But nobody is going to be doing that in the near future, because the race tuner that is out now for $120.00 is going to obsolete the chip business. With the race tuner, you plug in your lap top and change one or more of the parameters (eg., timing advance--can even make front and rear cylinders light off at different position of stroke, and can even control fuel/air ratio to each cylinder separately--can run the front cylinder richer than the rear!) and go for a test drive--right on your laptop, followed by a real test drive to get a feel for the laptop results. Then come back and change something else. The number of parameter setting combinations is close to infinite. Then when you make a hardware change on your bike you can start all over again!---------The value of the chips is Harley has already done all the simulations and is telling you these are the EFI ECM parameters you need for a given set of hardware. That's why your 103" SE with a high flow (that's your K & N) filter requires a different chip---you made a significant hardware change. In other words, unless you really are a wrencher, and are going to continue to play with hardware options beyond an air cleaner and pipes, you won't need a race tuner.