Bully Dog® 40400-105 - OBDII Block

51 reviews / Item # mpn1863754
Bully Dog® - OBDII BlockBully Dog® - OBDII BlockBULLY DOG® - Technologies Promo 602x420Bully Dog Authorized Dealer
● In Stock (65) - Usually ships within 24 to 48 hours
Universal Fit
Fitment Notes:
  • Not Vehicle Specific
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Bully Dog Accessories

OBDII Block by Bully Dog®. Interface between vehicle’s OBDII port under the dash and Triple Dog GT Gauge Tuner or Watchdog. Included with GT and Watchdog: order this only as a replacement or spare.

Bully Dog


  • Interface between GT or Watchdog and OBDII port
  • Plugs in under dash to interface with vehicle
  • Provides key-on power to device
  • Interface to pyrometer kit

This provides the interface between the vehicle’s electrical system, OBDII port, the optional pyrometer kit and the GT or Watchdog. One is included in the box with these devices: you do not need to order this to install a new unit. Order only as a replacement part, or to facilitate moving your GT or Watchdog between multiple vehicles

Bully Dog was formed in 1998 in Aberdeen, Idaho. The founders of Bully Dog – Michael, Phillip, and Daryl Klassen - were heavily influenced by their father Harold's interest in improving vehicle performance. Several years prior to the company's inception, Harold had experimented with increasing performance on his diesel farm tractor by injecting propane into the engine's combustion chamber. In 1998, Bully Dog's owners took this concept and developed and patented a safe and effective propane injection system to enhance diesel engine performance. These systems were first sold out of their farm shop, but as demand increased, they moved the company to another location and officially organized Bully Dog. Bully Dog's mission was now to be recognized as the leader in the diesel performance industry. With the introduction of electronic components and software to improve performance, they began to research new types of products like intake and exhaust systems to complement their electronic components. In 2005, the company expanded its range of products to include performance products for gasoline-powered vehicles. Bully Dog is now able to offer a complete performance package.

Part Number:

Vehicle Fitment

This part is universal
Year Make Model Fitment Notes:
ALL       ALL        ALL         This part is universal

    Product Reviews


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    Bully Dog® - OBDII Block
    Bully Dog® 40400-105 - OBDII Block
    Average Rating: 5 of 5
    5 of 5
    Gt Tuner OBDII Block
    Posted by (Denton, NC) /

    Fast shipping easy to deal with and easy to use would use them again. Thanks.

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    Bully Dog® - OBDII BlockBully Dog® 40400-105 - OBDII Block    
    51 reviews
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