TRD Cold Air Intake (CAI) Install 5th Gen 4Runner

Step By Step TRD Cold Air Intake Installation on 4Runner

This is a step by step guide and installation for the CAI on the 5th Generation 4Runner.

There was a lot of comments on the forums talking about the CAI not being compatible on the 4Runner. The TRD Intake does fit on the 2014-current 4Runner.

The whole process from start to finish took about 2.5-3 hours, and this was with two people. If you are doing this on your own, I would say you would be looking at 4 hours. The only difficult part about installing the CAI was the wiring.

Separating the wires and rerouting them along the loom was really the only detailed part of this whole process and even that was pretty easy.

• TRD CAI: Check Today’sPrice
• For the complete part list: Parts Details
• 2017-2018 Intake: 2017-2018 4Runner Intake

Complementary Modification:

• Pedal Commander Throttle Response Controller: Check Price

Step 1 – Pop off the Plastic Engine Cover with T logo

There are a few plugs that the cover snaps into, just gently pop them off all the way around. I think there were about 5 of them.

Step 2 – Remove Brackets & Screws

This may be the most time intensive part of the install. Removing the bulky, clunky portion of the air box requires removing all brackets and screws noted and circled below.

Step 3 – Remove Air Box Brackets

There are a total of thee brackets that are attached to the lower and upper air box. Grab a screwdriver and pop them off.

Step 4 – Remove Upper Air Box

Once the upper airbox clamps are off, you can remove the OEM upper airbox.

Step 5 – Unscrew/Mount Lower Air Box

Remove the lower airbox by unscrewing the lower screws and one bracket on the outside of the box.

Step 6 – Pull Out Lower Air Box

Make sure to tuck all your wires connected to the lower/upper airbox in a secure location. You will need to reuse these wires again to line the MAF (Mass Airflow Sensor).

Step 7 – Electrical Wire Separation

This portion is the most “complicated” of the install process. I say “Complicated” because it’s really not that hard. It just takes a bit of patience.

Step 7A – Electrical Wire Separation & Tape

1. Remove all the electrical tape from the MAF hub
2. Use a razor blade or sharp knife to slice open the connection tape
3. Be careful to not slice into any wires
4. Once sliced open, remove the excessive electrical tape
5. Start separating MAF (Mass Airflow Sensor) wires from other wires
6. Pull MAF wires down to the bottom where they draw from

CAI Install – Step 7B – Electrical Wire Separation, Split loom & Tape

1. Separate the MAF wires from bundled wires and loom completely
2. Make sure to bunch up both sections of wires and keep it tight
3. Wrap electrical tape around each section of wires
4. Re-loom both sections of wire
5. Loom sections looking clean and tight
6. Wrap loom with electrical tape and seal up

Step 8 – THE INTAKE INSTALL

Step 9 – Inserting Both Male Connections into Coupler

Inserting both of the male connections into the TRD intake coupler. This part takes some muscle grease. You don’t want to use any chemicals to help with pressing in the male connections because you don’t want any chemicals running through your engine. So keep the grease, lube and even WD-40 off the table and use your good ol’ muscle grease. Pictured here, you can see the pressure needed to push these male connections in.

Step 10 – Inserting Intake Coupler #1

Position the TRD intake coupler with male connections facing the cab so you can connect the OEM tubing.

Step 11 – Remove Plastic Piece from Tubing

Remove the plastic OEM tubing.

Step 12 – Attach Tubing to Coupler

Attach the new male connection to the OEM tubing.

Step 13 – Remove OEM Tubing & Insert New Tubing

Remove the OEM tubing & insert new tubing (Provided by TRD in the TRD Intake Kit) back onto the OEM part.

Step 14- Connect Tubing and Zip Tie Tubing

Connect tubing to the additional male piece of the coupler and zip tie.

Step 15 – Insert Airflow Accelerator

Insert the Airflow Accelerator into the open hole where the upper/lower airbox was located.

Step 16 – Remove & Save OEM Grommets from Lower Airbox

Step 17 – Insert OEM Grommets into new Lower Airbox

Step 18 – Install and Mount New Lower Airbox

Using the OEM screws, screw the new TRD Intake lower airbox back down to the body.

Step 19 – Drop in Air Filter & Attach New Box Clamps

Place the TRD Intake Air Filer into the lower airbox and attach new TRD Intake clamps.

Step 20 – Add Grommet & Filter Minder

NOTE: Don’t forget to add the grommet before adding the upper airbox down.

Step 21 – Remove OEM MAF (Mass Airflow) Sensor

Unscrew the OEM MAF (Mass Airflow Sensor) from the old airflow section.

Step 22 – Install OEM MAF (Mass Airflow) Sensor on Air Inlet Tube

Screw down the MAF onto your new TRD Intake inlet tubing.

Important Note: Use Loctite Threadlocker Blue 242 from Loctite Adhesives to screw down the MAF. This just prevents from accidental loosening.

Step 23 – Connect Both Couplers, MAF & Tighten Connections

Step 24 – Double Check All Connections and Couplers