The K&N 57-9036 is a 57-Series cold air intake for the 5.7L V8 in 2014-2015 Toyota Tundras, which the manufacturer describes as a direct upgrade to the factory air box system. It pairs a black roto-molded high-density polyethylene intake tube with a red oiled cotton-gauze High-Flow Air Filter that the manufacturer lists as a direct replacement. K&N's in-house dyno testing estimated a gain of 5.8 horsepower at 5,508 RPM and 5.73 lb-ft of torque at 3,796 RPM over a stock 2015 5.7L. Owners on user forums report that the gain is modest, so this kit is best bought for a washable filter, a slightly freer-breathing intake, and the engine sound it adds rather than for big power numbers. The manufacturer states it is street legal in all 50 states under CARB executive orders D-269-52 and D-269-90. Search terms: K&N 57-9036 Tundra 5.7 cold air intake, washable cotton gauze intake, 2015 Tundra 5.7L CARB legal intake, Tundra V8 OEM air box replacement.
Choose this kit over stock if you want a reusable filter you can clean and re-oil rather than replace, and a tube that keeps the factory air box in place. The manufacturer lists the filter as cleanable for up to 100,000 miles under normal highway driving, although that interval depends on your conditions. Fitment is the first thing to verify. The manufacturer's 2014-2015 Tundra notice covers both 4.6L and 5.7L V8 trucks, while its product listings show 5.7L fitment across a wider year range, so confirm your exact year and engine with the manufacturer before ordering. Installation is a bolt-in job that the manufacturer says takes about 60 to 90 minutes with basic hand tools. Owners on user forums warn that the open-element design is louder under load, especially when towing, so consider how much intake noise you are willing to live with.
The manufacturer lists this intake with CARB executive order numbers D-269-52 and D-269-90 and describes it as 50-state street legal. Confirm the executive order that matches your model year before purchase.
The manufacturer says the filter needs cleaning only about every 100,000 miles under normal highway driving. Dusty, off-road, or towing conditions will shorten that interval, so inspect the filter regularly.
Per the manufacturer's general installation guide for K&N cold air intakes, the factory mass airflow sensor is moved from the stock housing into the K&N adapter with the supplied gasket, then reconnected to the new tube.
The manufacturer's install guidance for the 5.7L Tundra lists a wrench, extension, flat-blade screwdriver, and Allen wrench, with an installation time of 60 to 90 minutes, so this is a manageable weekend job for a home mechanic. Disconnect the negative battery cable before starting, then unplug the mass airflow sensor and disconnect the EVAP and crankcase vent lines. Loosen the clamps at the throttle body and the air box, remove the factory tube, and move the mass airflow sensor into the K&N adapter with its gasket. Watch the mass airflow sensor wiring harness during reassembly so it does not stretch or rub against the fender, and make sure every clamp is tight so the tube does not leak unfiltered air. Note that disconnecting the battery can erase stored radio presets and other memory settings, so write them down first.
