E46 Ms42 Ms43 ecu tuning

B.A. Tuned ECU's!

We are BACK with custom tunes! Buy From the BEST; we have been tuning these cars for years and the speed of our Time-Attack E46 proves this point! Full tech support included, we are here to help your right foot make you smile! We are proud of our 100% positive feedback. 


We have teamed up with Belsky Autowerks to provide the best tuning and service available. Vlad is one of the best tuners we know, is very technical with his approach, and specializes in BMW tuning. When we decided to bring back tuning, we knew right away who we wanted to collaborate with. Vlad's expertise will help you get the most out of your M52TU or M54 powerplant safely and trouble free. 


Getting a custom tuned ECU is now simple. Just order and we will ship you an ECU that is ready to drop in and go. If you return your original ECU with your information, we will then refund you $40 for the core. 


We provide a plug-and-play, tuned, ready to go. Please choose from the options available when ordering, and contact us for any special requests. These ECU's also has the EWS deleted, so it can also repair vehicles with a bad ECU or EWS system without the need to visit a shop for expensive programming, or be used in a engine swap project. Just plug it in and go.


This ECU offers similar gains to the "Shark" tune, the AA tune, and makes the throttle respond like the "Sprint Booster" would, but for much less and way more options! Do not use in conjunction with the "Sprint Booster". For Off-Road use only. Options get the most out of headers and M50 manifold swaps compared to off the shelf tunes like AA and Shark. 


Now, lets go over the options:


ECU/Engine version:

MS42 comes in all 323 and 328 models. The 325 has a 2.5 and the 328 has a 2.8

MS43 comes in the following models, with the 325 being the 2.5 and the 330 the 3.0.

  • All E46 Xi models, regardless of year
  • E46 325 and 330 vehicles built before mid-2003. If your MAF sensor has 3 wires, you are MS43 
  • All E39 525 and 530 models
  • All 2003-2006 X3 E83 models
  • All 1999-2006 X5 E53 models with a 3 Liter engine


Intake Manifold: Select which you'll be using, we tweak the VANOS and other maps to get the most out of cars using our M50 manifold swap which can be found here. this will also allow you to use the normal E36 air temp sensor that comes with the m50 manifold instead of retrofitting the original plastic M52TU/M54 temp sensor: M50 Swap


Headers/SAP: If you are running headers, or plan on installing them later, select yes here. We will delete the downstream o2 sensors which monitor catalytic converter efficiency (removed with headers) and also open up the maps a bit to make up for the engine breathing a better. You can also remove the bulky secondary air pump with this option. With these options you wont get the check engine light when installing headers for some great power gains.


Rev Limit: Get that motor singing! This is a great option especially if your using headers and/or a M50 manifold. We do not recommend raising the rev limit above 6500 on vehicles without an oil pump solution, which can be found here: Oil Pump


Thermostat/Fan Temp Mod: These engines have an electronic thermostat and manual models have an electronic fan, so this makes adjusting the running temp a breeze. They came with super high target coolant temps for emissions tests, but if you are tracking your car or running hard, this makes it hard for the cooling system to keep up. With this mode you have a greater buffer as the motor will target a slightly lower temp. 


Increased Idle RPM: This is a great option if you have a single piece flywheel. These often create a chatter, but slightly raising the idle RPM makes this go away. 

Due to the intended use of high performance products, Seems Legit Garage, LLC. ("SLG”) products and each part thereof, are sold "AS IS” and with all faults. To the fullest extent allowed by law, SLG Racing Products makes NO written, oral, expressed, or implied statement of warranty or guarantee on any product or part sold. SLG will not be liable for any direct, indirect, incidental, consequential, or special damages, including but not limited to, damage, injury, loss of life, loss of property or equipment, loss of profits or revenue, or claims from any individual or entity arising from the use of any SLG product. 

RACING IS A DANGEROUS ACTIVITY AND PURCHASERS OF SLG PRODUCTS ACKNOWLEDGE THE INHERENT RISKS ASSOCIATED. SLG MAKES NO REPRESENTATIONS THAT ITS PRODUCTS CAN REDUCE OR ELIMINATE ANY SUCH RISK. SLG products are NOT FOR STREET, HIGHWAY, OR AIRCRAFT USE and are intended ONLY for race vehicles operated on closed-course facilities or race tracks with appropriate supervision of qualified technicians or mechanics to ensure that the safety needs of the race driver and others are met. SLG products could be combined with other products or parts which may not be suitable and could adversely affect performance of other race parts or the vehicle. The user shall determine the ultimate suitability and safety of the product for its intended use, and the user assumes all responsibility and risk in connection therewith. 

ECU/Engine Version
Intake Manifold
Headers/SAP Delete
Rev Limit
Thermostat/Fan Temp Mod
Increase Idle RPM?