THUNDERMAX

THUNDERMAX 21 UP TOURING HARLEY 309-591

2 wide-band Bosch 5-wire oxygen sensors (18 mm) with AutoTune connection harness
ThunderMax quick start easy install and printable comprehensive user’s manual
Never outgrow it - easily accomodates bike change
No Dyno required - automatically tunes for riding style and riding conditions
ThunderMax performance engine control module (ECM)
100% engineered and made in the USA
Easy to install and simple to use