Xtreme EPROM Performance Transmission Chip for 1991 BMW 850i E31

Xtreme EPROM Performance Transmission Chip for 1991 BMW 850i E31
Brand: Sawyer Tuning
Product Code: XT_BMW4
Availability: In Stock
Price: $49.95



Designed for the 1991 BMW 

E31 850i





Custom Chip Tuning



Stage 3 Xtreme Chip - Engineered specifically for Your Vehicle



This chip upgrades the stock transmission ECU software, providing smoother shifting.  



Works with Transmission ECU code model:




Compatible with Automatic transmissions only


Unlock your vehicle's hidden potential! Typical gains include:

  • Smoother Shifting
  • Improved Acceleration
  • Better 0-60 Times


Includes everything needed to install

  • 1  Stage 3 Xtreme EPROM Module, Custom programmed for YOUR vehicle
  • 1  Instruction / Install Sheet
  • 1  Antistatic Chip Case






Frequently Asked Questions


Do I need any special tools or automotive knowledge to install?

  • No! the Xtreme Chip  is 100% plug and play.
  • It is tuned for your specific vehicle make and model. 
  • Beware of for cheap $10-50 mega horsepower products. They are fake and are a plastic box with a .10 cent resistor.


Does this product work with automatic and manual transmissions?

  • Automatic only.


Will this product void my warranty?

  • No it will not void your warranty, many dealers frown on performance upgrades. 
  • However, the manufacturer cannot void your warranty for adding aftermarket parts. 

Can this harm my engine or vehicle electronics?

  • No. Our products have been dyno tested and proven to work with no negative effects on the vehicle. 
  • We guarantee this!








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