aFe® 54-81172 - Stage 2 Si Cold Air Intake System with Pro 5R Air Filter

51 reviews / Item # mpn669949
aFe® - Stage 2 Si Intake System
aFe® - Stage 2 Si Intake SystemaFe® - Stage 2 Si Intake SystemaFe® - Stage 2 Si Intake SystemaFe® - Stage 2 Si Cold Air Intake System with Pro 5R Air Filter Press ReleasesaFe® - Stage 2 Intake System - installation instructionaFe® - CatalogaFe® - Factory Tour Video 602x420aFe Authorized Dealer
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aFe Accessories

Stage 2 Si Cold Air Intake System with Pro 5R Air Filter (54-81172) by aFe®. The aFe Stage 2 Si Cold Air Intake System replaces your entire factory air intake system with a large high-flow aFe Pro 5R air filter, a totally enclosed airbox and a smoothly contoured, less restrictive intake tube. This system enables your engine to take in huge quantities of dense, cool, oxygen laden air. The result is better combustion, increased horsepower and torque, and a noticeable gain in performance.

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  • Improves airflow to your enginer
  • Isolates the air filter from engine heat, enabling it to take in cooler, denser air
  • Increases horsepower and torque, improves performance
  • Designed and tested for each specific application
  • Includes a conical high performance aFe Pro 5R air filter
  • Includes a precision designed molded, sealed plastic airbox and plastic intake tube
  • Comes complete with everything required for installation, including comprehensive instructions
  • Can be installed in 45-90 minutes with simple hand tools; no drilling, cutting or fabrication required
  • Limited 2-year warranty
  • Proudly made in the USA

The Stage 2 Si Cold Air Intake System is for those who want a substantial performance gain with less intake noise and a stock appearance. It replaces your factory, restrictive air intake system with a massive aFe Pro 5R air filter, a sealed plastic air box that isolates the filter from engine heat and quiets intake noise, and a rotomolded plastic intake tube with smooth bends for increased airflow volume. The increased flow of cooler air to your engine will result in noticeable gains in power and performance. Cooler, denser air contains more oxygen, and more oxygen in your engine's air intake charge means better combustion, resulting in greater engine output.

The Pro 5R air filter was designed to provide the maximum airflow possible, to enable your engine to make the most horsepower and torque. But aFe didn't achieve this by ignoring engine protection. The Pro 5R outperforms most other cotton gauze air filters with a 98.6% efficiency rating. The increased airflow and high filtration capability are the result of the Pro 5R's construction. It's made of 5 layers of progressively finer medical-grade cotton gauze.

Competitors use constant size mesh gauze in their filters, which creates voids/openings that can allow dirt to pass through. As the progressively finer layers of gauze are stacked in the Pro 5R, the randomness of the openings increase, minimizing spaces with no filter media. Dust accumulates on multiple layers, increasing overall dust holding capacity and filtration efficiency.

The pleats in the filter are evenly spaced for greater dust holding capacity and the tips are rounded for better airflow. They're also 30% deeper than comparable aftermarket air filters for longer service intervals and greater dust holding capacity. The sealing surface and supporting structures are made from 100% polyurethane, to withstand extreme engine temperatures.

The one-piece sealed plastic airbox may install in the same location as the factory airbox, but there the similarity ends. The Stage 2 Si airbox is much larger inside in order to include the largest aFe Pro 5R filter possible. The air box also features strategically located openings and scoops to ensure that only the coolest air is forced into the air filter for greater efficiency and performance. And enclosing the air filter also results in less intake noise. The Stage 2 Si airbox installs easily; no cutting or drilling is required, and it’s attached with quality stainless steel hardware supplied with the kit.

A specially developed 3-angle velocity stack smoothes the airflow transition from the air filter to the rotomolded intake tube. The precision design and smooth contours of the intake tube maximize airflow volume and speed for optimum power gains. The intake tube also features a precision tuned MAF sensor pad, which will not affect engine performance or cause a CHECK ENGINE light.

The aFe Stage 2 Si Cold Air Intake System comes complete with everything necessary for installation, including comprehensive instructions. It's backed by aFe's limited 2-year warranty and made in the USA.

aFe® (Advanced Flow Engineering, Inc.) manufactures performance products for late model cars, light trucks and SUVs. The company was founded in 1999 with an initial concentration on high performance air filters. Since then, the company product line has broadened to include cold air intakes, fluid filters, exhaust systems, intake manifolds, intercoolers, programmers, differential covers, transmission pans and throttle body spacers. The team of engineers, machinists, production and sales people at aFe® have many years of experience in their respective positions, and together work to ensure they produce the best automotive products on the market.

Part Number:

Vehicle Fitment

This part is compatible with 12 vehicle(s)
Year Make Model Fitment Notes:
2015 Toyota Tundra
  • 4.6L / 5.7L
2014 Toyota Tundra
  • 4.6L / 5.7L
2013 Toyota Tundra
  • 4.6L / 5.7L
2012 Toyota Tundra
  • 4.6L / 5.7L
2011 Toyota Sequoia
  • 5.7L GAS
2011 Toyota Tundra
  • 4.6L / 5.7L
2011 Toyota Tundra
  • 5.7L GAS
2010 Toyota Sequoia
  • 5.7L GAS
2010 Toyota Tundra
  • 4.6L / 5.7L
2010 Toyota Tundra
  • 5.7L GAS
2009 Toyota Sequoia
  • 5.7L GAS
2009 Toyota Tundra
  • 5.7L
2009 Toyota Tundra
  • 5.7L GAS
2008 Toyota Tundra
  • 5.7L
2007 Toyota Tundra
  • 5.7L
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Product Reviews


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aFe® - Stage 2 Si Intake System
aFe® 54-81172 - Stage 2 Si Cold Air Intake System with Pro 5R Air Filter
Average Rating: 4.8 of 5
4.8 of 5
Awesome Intake
Simple to install, sounds great, and increases the power.
ZPosted by (Monroe, NC) /
2010 Toyota Tundra
Was this review helpful for you? Yes
aFe® - Stage 2 Si Intake SystemaFe® 54-81172 - Stage 2 Si Cold Air Intake System...    $425.00
51 reviews
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