ThunderMax® is complete system designed specifically for EFI equipped Harley Davidson® motorcycles.

This highly advanced, stand-alone tuning system utilizes proprietary AutoTune technology specifically designed to interface with wide-band oxygen sensors to correct abnormal A/F readings over a wide range of throttle positions and RPM ranges to prevent over rich or lean conditions.

ThunderMax® is made in the USA and comes assembled, no wire-cutting or splicing required to install. Replaces factory ECM and narrow band oxygen sensors.

*Supports RDRS function on 2019-2022 models.

No RDRS function for Tri-Glide Models- 309-588 fitment only for Tri-Glide 2017-2018 models only.

Not legal for sale or use in California on any pollution controlled motor vehicle.

Not legal for sale or use on any EPA pollution controlled motor vehicle.