The K&N 77-2591KP is a high-flow performance air intake for 2015-2020 Ford F-150 trucks with the 5.0L V8 fuel-injected engine. The manufacturer positions it as a replacement for the factory air filter and intake tube, using a mandrel-bent aluminum tube with a bright mirrored finish and a washable, oiled cotton-gauze filter. It is a bolt-on kit built for the F-150's stock mounting points, so it suits owners who want a cold air intake without a tune or custom fabrication.
Compared with the stock airbox, the manufacturer cites dyno-based estimates of about 13.86 HP at 4553 RPM and 15.1 lb-ft of torque, so treat those as estimates rather than guarantees for your truck. Against a cheaper disposable paper filter, the reusable oiled element is rated to go up to 100,000 miles between cleanings under normal highway driving, which is the durability case for the higher price. Owners on user forums report that a loose seal between the filter box and the hood can cause a whistle under throttle, so check that seal during install. Searches for a 2015-2020 F150 5.0 cold air intake, a K&N 77 Series F-150 intake, or a reusable 5.0 intake filter lead to this kit.
The manufacturer lists this kit for the 2015-2020 Ford F-150 equipped with the 5.0L V8 fuel-injected engine.
The manufacturer lists a CARB EO number for this kit, but legal status varies by model year and state. Confirm with the manufacturer before installing it in a CARB state.
The manufacturer states the filter needs cleaning about every 100,000 miles under normal highway driving. Dustier or off-road conditions call for more frequent checks.
The manufacturer's installation instructions state that this kit was not designed to fit vehicles with a body lift.
The manufacturer says a typical installation takes 60 minutes or less with simple hand tools, and the install sheet calls for a flat-blade screwdriver and a 4mm Allen wrench. Disconnect the negative battery cable first, but note that doing so erases pre-programmed electronic memories, so write down your radio presets and other settings beforehand. The install steps also call for disconnecting the EVAP vent and crankcase vent connections, loosening the hose clamps at the throttle body, and releasing the clips that hold the upper air filter inlet and factory intake tube. Use only the hardware supplied in the kit; the manufacturer warns that skipping the instructions or substituting hardware can damage the intake tube, throttle body, or engine. Owners on user forums recommend checking the filter box seal against the hood once the intake is mounted.
