RENNtech ECU+ Upgrade | X167 | GLS 63 S AMG EQ Boost | 745 HP / 767 LB-FT | 4.0L V8 BiTurbo EQ Boost | M177 | MY2021-2023 mercedes-benz-cls-class--257---2019-present--cls-450-esr3048959 Also included in the R1

Also included in the R1 Performance Package for the 190 AMG GT C

The RENNtech Hand-Held Suspension Module (HSM) is designed to work with the Mercedes Airmatic Suspension

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RENNtech ECU+ Upgrade | X167 | GLS 63 S AMG EQ Boost | 745 HP / 767 LB-FT | 4.0L V8 BiTurbo EQ Boost | M177 | MY2021-2023 mercedes-benz-cls-class--257---2019-present--cls-450-esr3048959 Also included in the R1ECU+ Upgrade Up to 745HP 767 LB FT Gains: +97 HP & +54 LB FT RENNtech HHT (Hand Held Tuner) allows you the unlimited ability to switch between tuned and stock ECU programming without ECU removal! RENNtechs proprietary tuning module contains both the Tuned file as well as your vehicles Stock file. The module plugs directly into the OBD2 port and delivers the file you choose directly to the ECU. Programming takes only a few minutes and the vehicle can