K&N Air Filter and Intake System
Published by Trails Less Traveled on April 9th, 2004
&Nh2. INTRODUCTION
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K&N Engineering offers a FIPK (Fuel Injection Performance Kit) for the 2.7L 4-cylinder engine in the Trails Less Traveled Tacoma. K&N also makes performance intake kits for the 2.4L, 3.4L and 4.7L Toyota truck motors, along with many other popular applications. This article covers the first of many engine performance upgrades that we have planned for the truck.
The FIPK systems are designed to replace the choking OEM intake plumbing, air-box and paper element. K&N claims their FIPK kits can result in power gains of up to 10% or more on some applications. Since we didn’t have a Dyno at our disposal, we can’t say exactly how much power the truck gained; but we can verify that the K&N FIPK definitely improves airflow and allows our motor to breathe much easier.
All K&N air filters are cleanable/reusable, and come with a 10yr./million mile warranty. Other features include increased gas mileage, 50 State smog exemption and a deep throaty sound when you are on the throttle. K&N includes a “Filter Re-Charger” kit with all their FIPK’s that includes a bottle of filter cleaner and enough filter oil for several future cleanings. It is always nice to get a bolt-on product that comes with its own maintenance kit!
INSTALLATION
The FIPK is designed to re-use your factory MAF (Mass Air flow) sensor and throttle body, so its a simple “plug and play” operation that should take about an hour to complete. Depending on your application, you may have to drill one 3/4” hole in the K&N intake tube for the air temperature sensor. K&N provides step-by-step instructions with each kit but the supplied pictures are small and black & white. We will provide large color images to help illustrate the process.
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This is the entire FIPK kit for the Toyota 2.7L 3RZFE complete with the “Filter Re-Charger” kit for future maintenance.
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Because the intake system has several electrical connections, the first step was to disconnect the battery’s negative terminal. After that we removed the air temperature sensor from the air-box.
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The next step was to unplug the wiring harness from the MAF sensor.
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Then we removed the three bolts that hold the factory air-box in place.
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After that we disconnected the breather for the evaporation canister from the airbox.
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We loosened the hose clamps that hold the intake tubing between the MAF sensor and the throttle body. Then we detached the MAF sensor wiring harness from the intake plumbing.
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At that point we were able to remove the flexible rubber intake elbow pipe.
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There are two bolts located on the under side of the silencer that needed to be undone in order to remove the hard intake pipe/silencer unit.
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We removed the crankcase breather hose from the hard pipe by squeezing the clamp with channel-lock pliers and pulling the breather hose off.
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After the small vacuum line for the fuel pressure regulator was disconnected from the side of the silencer, the hard pipe/silencer was removed.
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This is what our engine bay looked like with all stock parts removed.
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Next we needed to remove the MAF sensor from the air-box. After we removed the four nuts, the MAF sensor slid right off.
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We bolted the MAF sensor to the K heat shield with the provided hardware. The air horn is pre-tapped so the four bolts thread right in.
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We installed the flexible trim material to the perimeter of the heat shield. When the hood is closed the shield isolates the cone filter from excessive engine heat.
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We bolted the supplied rubber vibration isolator to the heat shield as shown.
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Next bolt the included 90? angle bracket into the stock air-box mount. We didnt tighten the hardware at this point because it needs to be aligned with the heat shielding.
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Next we bolted this bracket to the radiator support using another stock air-box mounting hole.
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We slipped the small end of the silicone reducer over the MAF sensor and fastened it with the supplied hose clamp. Then we installed the heat-shield assembly as shown. Don’t forget to tighten all the hardware after you have it properly aligned.
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Since our truck had an air temp. sensor we needed to drill a 3/4” hole in the K&N intake tube. The intake tube has a small dimple in the fused seam indicating where to center the drill bit. This is what the intake tube should look like after drilling. Install the supplied grommet into the hole drilled in the intake tube.
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Slip the flexible connector over the intake tube and fasten with a hose clamp. Install the tube and fasten the flexible connector to the throttle body and the MAF sensor.
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Re-install the crank case breather to the intake tube, reusing the factory clamp. Thread the 1/8” supplied white plastic vacuum barb into the hole nearest the throttle body on the intake tube and attach the fuel pressure regulator vacuum hose.
NOTE: These next few steps may be different for each application, refer to K&N’s manual for your specific vehicle.
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Thread the supplied 3/8” white plastic vacuum barb into the hole nearest the MAF sensor on the intake tube. Attach the supplied short piece of 3/8”ID vacuum hose to the barb installed in the last step then attach the supplied 3/8”-3/8” black plastic hose mender to the supplied short 3/8” vacuum hose and attach to the factory evaporation canister vacuum hose.
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Plug the air temperature sensor into the drilled hole in the intake tube (the sensor should fit snugly into the grommet). Then plug-in the MAF sensor wiring harness.
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Slip the K&N cone filter over the air horn and fasten with the supplied large hose clamp.
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Secure the MAF/air temp sensor harness to the AC condenser line with a zip tie to keep the wiring harness away from the hot exhaust manifold.
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Reconnect the negative battery cable and the installation is complete. This is a dramatic improvement over the stock components.
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K&N provides a self-adhesive metal decal displaying the CARB exemption number to be attached under the hood. We haven’t installed our sticker yet because the truck is undergoing serious changes over the coming months and we want to be sure the decal gets put somewhere permanent.
This Article was originally published on Off-Road.com March 2004
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