BMW MS45.0 to MS45.1 ECU Coversion

Overview

BMW's MS45.1 ECU runs wideband primary oxygen sensors rather than the narrowband sensors used by MS45.0. This allows the MS45.1 ECU to apply fuel trims at full load, ensuring AFR is metered to a precise degree, which is massively important for engine reliability and performance. Unfortunately, ECUs the use narrowband sensors (such as MS43 and MS45.0) must guess the AFR at full load rather than measure it. This can lead to huge inconsistencies in targeted AFR versus actual AFR, detonation, or reduced performance.

Rather than run blind, convert to MS45.1 and use the best tune on the market! MS45.1 plug-n-play conversions are now available!

Purchase includes a refurbished wiring harness and MS45.1 ECU programmed to be completely plug and play with your car. No cutting or soldering required! If you have previously purchased a Severn Tuning ECU tune, we will copy over the settings to your new ECU. Otherwise, the ECU will contain a factory tune compatible with a stock vehicle.

Experienced mechanics can complete the installation in approximately 30 minutes. We recommend enthusiasts budget two hours.

We are actively working to add sport mode functionality to MS45.1 ECUs. Bosch wideband oxygen sensors must be purchased separately.

Disclaimer - Flash tuning is separate from coding and diagnostics. It will not solve underlying mechanical or electronic issues, and in some cases, it can make problems worse. We highly recommend you consider tuning to be a final ECU calibration and the very last step when optimizing your vehicle. Recommended for off-road use only!