K&N Performance Air Filter for 5th Gen 4Runner

5th Gen 4Runner Performance Air Filter - K&N

K&N Performance Air Filter Swap on 5th Gen 4Runner (TRD or K&N?)

Performance in an Air Filter? Really? Well, kinda.

The K&N filter or any performance air filter for that matter is designed to increase airflow. Anytime you can increase airflow on your 4Runner, this is a good thing. We are always looking for ways to increase airflow and power performance on our 4Runner. The K&N does help with this.

You can expect to see as much increase in power as you would think, not much. The power you will see is nothing compared to a TRD Intake or a new Magnaflow exhaust system, or even a Magnuson SC. But, it is definitely nice knowing that you are not reusing a bunch of syntactic paper every time you get a service.

Reusable air filters really are great for the environment. If every vehicle in the world had reusable filters, think about the amount of waste we would reduce.

Your truck should run more efficiently with a better air filter. This is all relative though. You will hear a back and forth debate on both sides of the fence here. Some guys would never buy a K&N filter and some would buy one for every vehicle they own.

Air Filter Options

At the end of the day, I would buy a K&N Intake if I had to do it over. We purchased the TRD Intake in 2016 and at first loved it. But, we had not heard the K&N intake on another 4Runner.

I recently heard the K&N intake on another 4Runner in person and loved the sound. It was much more throaty and had a little rasp to it.

If you are on a budget and not looking to go for a full intake, then consider grabbing an aftermarket air filter.

The K&N Performance Air Filter

K&N claims to have some of the worlds best materials on the market and rightfully so. There are millions of them sold every year. Cars, trucks, and SUVs everywhere depend on K&N to get the job done. Whether you have a filter or an intake, you can trust that you are running a quality product. 

This specific high-flow original cotton filter was invented by their engineering team. This product is designed to reduce air restriction, allowing an engine to breathe easier than traditional paper filters. 

This is completely washable, reusable and there’s a lifetime 1,000,000-mile limited warranty.

Using one of these filters can actually increase horsepower and acceleration. This is what K&N claims but I wouldn’t count on racing down the freeway after you install one. In other applications such as the intake, yes.

Millions of car, truck, and SUV owners and professional racers choose K&N and Intakes over restrictive disposable air filters and stock air boxes. They do make bad ass products. 

Also, Toyota outsources their performance air filters to companies like K&N. Just like they outsource their superchargers to companies like Magnuson supercharger‘s as well as outsourcing their intakes to companies like AFE. 

Reusable Filters

Over 100 million disposable air filters are discarded each year. K&N invented reusable cotton to help reduce the waste problem in America, and have sold over 20 million since 1969. These filters are washable, reusable and will last for the life you drive them. Instead of paper or synthetic materials, these filters use multiple layers of treated cotton gauze.

The natural characteristics of cotton help create a remarkable system that can provide outstanding performance and very high air flow rates which alternately increases your horsepower and acceleration. 


Clean every 50,000 miles. This requires cleaning every 50,000 miles for highway use, more often for dusty conditions or for general loss restriction. For detailed cleaning instructions visit the K&N website.

Tough on Dirt

The design: thousands of microscopic cotton thread’s absorbency and specifically formatted oil to create a powerful filtering method. As part of K&Ns performance and commitment to protecting our 4Runner’s engine, they consistently test the efficiency using ISO 5011 test protocols.

The 1,000,000 mile limited warranty

K&Ns are built so well that they guarantee them for 1,000,000 miles. Yes, you read that right, they guarantee their product for over 1,000,000 miles.

This means you can call at any time if your product fails and they will send you a new one at no additional cost. You can highly count on this company to deliver quality products time and time again for our off-road vehicles.

Step #1 – Unhook OEM air box brackets x4

5th Gen Air Filter Replacement Step #1 - Unhook OEM air box brackets x4

There are four tabs on the stock 4Runner air box. Start by lifting the brackets on all four corners. Each corner of the airbox will lift up.

Step #2 – Disconnect MAF Sensor and Loom Bracket

5th Gen Air Filter Replacement Step #2 - Disconnect MAF Sensor and Loom Bracket

You do not have to unclip your MAF (Mass Airflow) sensor and the wiring loom that it is connected to. I recommend doing this, just in case. With the MAF disconnected and the tab on the loom disconnected, you will a little more flexibility from your stock airbox.

Step #3 – Lift out OEM Filter

5th Gen Air Filter Replacement Step #3 - Lift out OEM Filter

Pop the lid on your airbox and then pull the OEM paper.

Step #4 – Swap in New K&N

5th Gen Air Filter Replacement Step #4 - Swap in New Aftermarket Filter

Swap in your new K&N.

Step #5 – Connect MAF Sensor, Loom Bracket, and Shut Box

5th Gen Air Filter Replacement Step #5 - Connect MAF Sensor, Loom Bracket, and Shut Box

This will take you about 5 minutes. This replacement is incredibly easy. If you are looking for a quick little mod to do before work, this is about as simple as it gets.

I know there are some of you out there who would never install an aftermarket filter. And, some of you that have already installed and seen no problems whatsoever.

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1 year ago

Oil will get on the MAF too.. I have been using a K&N on a speed density motor since 1996. You have to clean it often, and their oil isnt cheap.

Phaht Dohhng
Phaht Dohhng
2 years ago

I use the non oiled synthetic AirRaid filter and Holy Crab Cake it’s far better to me after using K&N maybe it’s old article but my Toyota dealer mechanic suggested it after laughing at my “aftermarket” filter. There’s no difference in fuel mileage in either but I drive like somebody you think is high on the white horse trying to get away from the giant seahorses in his rear view mirror, what IT DOES DO is give it wicked noticeable throttle response and sound, I gotta say it protects better after cleaning the filter at 5k miles (I’m overkill on maintenance) without driving different routes or terrain as with the K&N it had more crap noticeable trapped so that’s another plus.

5 years ago

I dropped in a new K&N filter last week and have noticed a LITTLE increase in acceleration/throttle response and a slight bump in fuel mileage. What I have really noticed is a very annoying whistle when I accelerate between 1500-2500 RPMs. Has anyone ever had this problem? If I can’t fix it I’ll probably have to go back to the stock filter.

6 years ago

K&N Filters — While they may improve air flow, it comes at a price. They do not filter dirt particles as efficiently as a paper filter, and the oil build up in the intake is just nasty, and with it comes dirt stuck to the oil. I loved mine, at first, until I put enough miles and exposed it to enough dirt to find out the disadvantages of a K&N

Great site BTW!

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