Banks Power Derringer Tuner with iDash DataMonster (66793)

A tuner is a small box that plugs into the diagnostic port under your dash and changes how the engine computer manages fuel and boost, so the truck makes more power without swapping any physical parts. This one comes bundled with the iDash DataMonster, a screen that mounts on the dash and shows live readings like boost pressure and exhaust temperature plus logs that data over time, so you can watch what the tune is actually doing to the engine instead of guessing.

why this one — Banks builds this specifically for the 2017-2019 L5P Duramax, which is the first-generation body style of the HD Duramax before GM redesigned the truck in 2020, so it will not fit a 2020-and-newer Sierra HD even though both use an L5P engine. Six power levels mean you can run it mild while towing a trailer and turn it up when the truck is empty. Banks says it needs no ECM reflash and leaves no trace if removed, which matters for warranty and resale. One thing to flag: Banks calls it 50-state compliant but does not publish a CARB Executive Order number on this product page, so this listing makes no street-legal claim beyond what Banks states.