McLaren M838T M-Engineering OBD2 ECU Tune


Unlock extra power and increased response on your McLaren with an M-Engineering ECU Tune and do it easily through your OBD2 port without removing your ECU! Safely enhance the enjoyment of your vehicle with no drawbacks. Make the most out of your SOUL performance upgrades through software optimization. Enjoy additional features including the ability to read and clear faults, datalog, view live data, and flash back to stock at your convenience.

NOTE: ECU must be shipped to M-Engineering for initial unlocking before OBD tuning can be performed.

SKU: MCL.M838T.MECU Categories: , , ,


The M-Tuner is the first, and only, at-home OBD flashing utility! Developed by M-Engineering, M-Tuner integrates all features of the M-Logger and adds them with the ability to flash anytime, anywhere!

What’s Included?

  • M-Tuner Dongle for OBD Flashing
  • USB Cable
  • M-Engineering maps built for your M838T (see calibration notes)
  • On-the-fly Live Map Switching
  • M-Engineering Support

Vehicles supported by this version of M-Tuner:


The Following exclusive features are included with the M-Tuner Package for 3.8L McLarens:

  • Live Map Switching
    • This includes stage calibrations for Stage 1 & Stage 2 vehicle configuration. Remote custom tuning is available for different vehicle configurations as well.
    • Performance Stage 1 & Stage 2 calibrations include the following map slots by default:
    • Slot 1 – 91 Octane
    • Slot 2 – 93 Octane
    • Slot 3 – 100+ Octane
    • Slot 4 – Valet (Limits boost, load, and throttle)
    • *Please contact us at time of ordering if you wish to have different map slots.
  • Datalogging
  • Live Data
  • Clear Faults
  • Dyno Mode Enable/Disable
  • Auto Start/Stop Disable
  • Left Foot Braking
  • Kickdown Disable
  • Loud Start

More custom features for racing and motorsport applications can be added and are located under the M838T Motorsport Tuning Package.  Features such as Rolling Anti-Lag, Boost by Gear, etc…

*M-Tuner requires a one time bench procedure which requires the ECU to be sent to M-Engineering HQ.

Pro Tuning and custom calibrations are also available for those who are looking to optimize their McLaren for parts configurations or fuels not listed in our map notes.


Disclaimer: You accept responsibility and risks of any tunes and added features by M-Engineering. If you are not the end user of the car, you will be solely responsible for notifying the purchaser and/or customer they also accept the responsibility and risks of these and M-Engineering is not liable. M-Engineering is also not liable for voided warranties due to installation of our products.

Return Policy: All sales are final and non-refundable. M-Engineering provides specific software calibrations for individual vehicle use and is not liable for misuse or vehicle behavior due to installation error or mechanical issues. M-Engineering will work one-on-one with individuals to assist with remote diagnosis to vehicles to our best ability and advise next-action steps as needed. End-users are responsible for vehicle maintenance, integrity of aftermarket parts installation, and having their vehicles up-to-date with their manufacturer’s latest updates and TSB’s.