Motorcycle Repair: vn2000, aftermarket pipes, fuel injection system

Question
when putting on new exhaust pipes on a fuel injected bike, do you have to re-calibrate the system?

Answer
If they are factory replacement pipes, no you do not. If they are aftermarket, yes you do. Most aftermarket pipes provide less resistance to the exhaust gases as they pass through. This leads to a lean condition in the engine as there is less back pressure pushing against the exhaust side of the engine. The fuel injection system has to be remapped to adjust for this loss by changing the fuel curve in the program.