hi all,

when i first got my bike i had a thundermax with autotune and a stage one aircleaner fitted to the bike the bike had already had after market slip ons on it. im wandering how shops/harley mechanics get away with out installing the bypass moduals on the fuel injection and the exhaust valves when they disconect them?

i have talked to a few different mechanics and they seem to have different views on this , some say they should have the bypass moduals for the engine management faults light to work and others say that they dont need them including the shop that installed it  but the shop that installed it dont seem to want to tell or give any secrets away.

so can anyone shed some truth on this.

 i forgot to mention that the engine management light appears to be working it comes on when the igniton is turned on and goes off after the fuel pump has primed.