RENNtech ECU+ Upgrade | 167 | GLS / GLE 580 EQ Boost | 592 HP / 704 LB-FT | 4.0L V8 BiTurbo EQ Boost | M176 | MY2020-2023ECU+ Upgrade Up to 592 HP 704 LB FT Gains: +68 HP & +120 LB FT RENNtech HHT (Hand Held Tuner) is the number one ECU programmer for Mercedes Benz and AMG. Do it yourself tuning, no ECU removal or mechanical modifications necessary! 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