TRD Cold Air Intake Install 5th Gen

 In 5th Gen Mods, Accessories, Install, TRD

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

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.

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

TRD Cold Air Intake Install - Step 1

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

CAI Install - 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

CAI Install - 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

CAI Install - 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

CAI Install - Step 5 - Remove 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

CAI Install - 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

CAI Install - 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

CAI Install - Step 7A - Electrical Wire Separation

  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

CAI Install - Step 7B - Electrical Wire Separation

  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 9 – Inserting Both Male Connections into Coupler

CAI 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

CAI Install - 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

CAI Install - Step 11 - Remove Plastic Piece from Tubing

Remove the plastic OEM tubing.

Step 12 – Attach Tubing to Coupler

CAI Install - Step 12 - Attach Tubing to Coupler

Attach the new male connection to the OEM tubing.

Step 13 – Remove OEM Tubing & Insert New Tubing

CAI Install - 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

CAI Install - 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

CAI Install - 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

CAI Install - Step 16 - Remove & Save OEM Grommets from Lower Airbox

Step 17 – Insert OEM Grommets into new Lower Airbox

CAI Install - Step 17 - Insert OEM Grommets into new Lower Airbox

Step 18 – Install and Mount New Lower Airbox

CAI Install - 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

CAI Install - Step 19 - Drop in Air Filter

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

Step 20 – Add Grommet & Filter Minder

CAI Install - 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

CAI Install - 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

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.

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

Step 23 – Connect Both Couplers, MAF & Tighten Connections

CAI Install - Step 23 - Connect Both Couplers & MAF

Step 24 – Double Check All Connections and Couplers

CAI Install - Step 24 - Double Check All Connections and Couplers


If you have any additional questions, comments or suggestions, please leave your comments below. Did we miss something? Please let us know.

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Showing 31 comments
  • Rob Cushman

    I just installed the TRD CAI on my 2018 TRD Off-Road. It was an easy install, looks great, and sound awesome. Great job on the instructions, I’ll be installing the Magnaflow exhaust later this week. Thanks for the DIY guides.

    • Bgreene

      Awesome! Glad they are helping. Feel free to send us an image or two of the install so we can share with everyone. Thanks, Rob!

    • Cal

      Was the install just a remove and replace?did you have to do any cutting on any Sheetmetal.

      • Brenan - Trail4R

        Cal, I will reach out to Rob and see what the details were on this build/ install for the intake.

    • Enrique

      I’m so excited to hear you installed it in a 2018 4runner TRD off road, I just got one since the pro was 4 month decided on the off road and I’m ordering this for my whip. I will post once installed maybe I will through a video also. …

    • Matt

      Rob did you use part# PTR03-89100 for your TRD Off-Road install?

  • Michael West

    The local Toyota dealership said the TRD Cold Air Intake (PTR-03-8911) will not pass smog certification here in California, yet two other dealerships said “no problem.” Somebody else said save the stock one and change it out before inspection, which seems like too much work. The service guy said “it’s not that the engine itself wouldn’t pass, but that the part isn’t “certified,” or words to that effect, and it is because of this that it wouldn’t pass. Any help?

    • Brenan - Trail4R

      Yeah, so the TRD intake is a touchy subject these days. We tried to buy one on Amazon and Amazon wouldn’t ship it to us. I had to buy it from another online parts store and they said it was because of emission standards. In regards to getting your 4Runner smogged, I have not crossed that river yet. We really don’t have much input in the smog section. If anyone else does that is reading this, please drop a comment. I guess we will see what happens moving forward with California Emission standards. But, if you are in any other state, you don’t have to worry about it. Thank you, California!

      • Junnie

        I live in California and if this unit does not come with a CARB approved sticker from TRD then it will be an automatic visual fail. I’m sure it will pass but because it was not CARB approved the technician will automatically fail you no exceptions.

  • Eric

    I installed this on my ’17 TRD Pro, I am noticing a little bit of a whistle when throttling around 1800-2300 rpm. Have you noticed/heard of this and know a potential fix?

    • Brenan - Trail4R

      Yeah, that is normal. The Intake is supposed to do that. The intake whistle is totally normal. On the factory airbox, Toyota designed the box to decrease the amount of noise. The whistle has always been there, you just were not able to hear it until now. Now that there is less restriction on the airflow, the whistle is much more noticeable. As you throttle, you are opening the intake manifold for more airflow, as this opens it creates a little whistle. The bottom line is that the whistle is part of the factory intake manifold, not part of the TRD cold-air intake system, or even the factory air intake, for that matter. The whistle will always be there, an Intake just makes it more noiticable.

  • William

    What are the estimated gains from this mod? Does TRD give you details on how much HP this will generate?

    • Brenan - Trail4R

      Good question. After everything on the website about the Intake, I don’t think we have touched on specifics. For actual HP gains, you can expect anywhere from 4-10hp. Much of this depends on what else you are running on your 4Runner. If you are running a catback exhaust, the Intake will do better, increasing gains. Same goes for headers. If you are running headers, your intake will run much more efficient, push much more dense air, creating more hp gains. On average, I would say the gains are minimal (6hp on average maybe) but in a 4Runner, minimal can mean a world of difference.

  • Blake

    Just installed on my 2018 TRD Off-Road. Installation was pretty simple, there was nothing weird to move around or anything… it was just install and replace. The most time consuming is removing the wrap around the wiring and then rewrapping. On the grommets, I had a small screwdriver handle that fit in the rubber grommet hole and was able to push the metal insert out one end just enough that the other end became that much more “squishy” and that made it so much easier to remove from the old box and install in the new box. This took maybe an hour. The instructions on this page will work perfectly fine for a 2018. I took it for a quick spin afterwards and you can definitely tell the difference, at least for myself, I can. Hopefully I’ll be able to see some MPG gain besides it feeling a little more responsive.

  • Blake

    Just a heads up… for any California guys looking to installing one of these – I installed mine, I purchased it from a California and just received a California compliant sticker from the Toyota dealer for use on my intake. I can send a picture of the sticker if anyone is curious.

  • Jason

    Tried to get a CAI from my local dealer ($408) here in CO and they told me the closest ones were in TX and Toyota has them on backorder with “99” on order. They said it could mean a few things, 1) They are behind on production, 2) they found something wrong and are fixing it or 3) They are coming out with a new product. Either way, unless I order online Im not getting one anytime soon.

    • Matt

      Experienced the same – I didn’t leverage my local dealerships (price) but ended up attempting to buy through 2 online shops – only to be told they were no longer in stock. Third time was a charm for me.

      Regarding the lack of availability – I did inquire and was told that it’s not related to a recall, just a backorder from Toyota with no clear timeline at the present moment.

  • Bill

    Three questions: 1) I believe this has been beat to death, but the amazon link for PTR03-89100 indicates “does not fit your vehicle” (2015 Trail Prem). From all I’ve read it should fit so I plan to proceed. 2) does the plastic logo engine cover fit back on after installation of the TRD intake or not necessary? and 3) what are the attachments to the OEM intake tube (visible in Step 2 photo) that are not on the TRD intake?

    • Brenan - Trail4R

      Bill, yeah you are good to go man. Yes, the engine cover does fit back over. I think you are referring to the resonator, you don’t need this.

  • Kyle Wilkins

    Hi I was wondering if the dimensions are the same? I am getting a battery relocation kit and wanted to make sure my starter battery would fit over their still. Awesome article.

  • Shaf Syed

    @Brennan,you not kidding about the pressure required to get the intake cloupler in. I spent hours just in that! I don’t think it makes a difference but I do not think you pushed enough of it though. I did not stop after first tapered end. I pushed it even over the next ring which is why it took hours. I did that to both the large and small OEM tube inserts. I did not think that the final look should have any part of the inserts exposed. So when I connected the hoses they sit flush to the intake cloupler. Thanks for providing the great illustrations and I used yours in conjunction with the instructions that came with the package.

    • Brenan - Trail4R

      Shaf, nice thanks. I will take a look and see how mine are positioned and how they are holding up.

  • Chris

    For all having trouble finding these in stock or on back order, my tech at the toyota shop by me hooked it up! You can order all of the parts separately, including the C.A.R.B. sticker in CA at once and get it in a day, if you buy the “kit” expect to wait a while. I literally ordered at 3pm on a Thursday and had everything Friday afternoon!

  • Shawn Pfeiffer

    I first want to say that your site here is awesome, it has given me a lot of ideas for my 4runner. I have read the articles on the TRD CAI, and what vehicles it has been installed on. I just wanted to get some more confirmation that the TRD CAI will fit on a 2018 TRD Pro. Thanks.

    • Mark

      I just installed the TRD CAI on my 2018 TRD Pro without any issue. There were some slight changes on where to secure the wire vs the directions that came in the box, but dealing with that was simple and straight forward.

  • Aaron

    Just installed the TRD intake on my 2019 4Runner and it fits just like all the previous years.

  • Josh

    Does the OEM MAF sensor need to be re-tuned with the TRD CAI? It seems as though it would only be turned for stock airflow?

  • Matt

    I just installed the TRD CAI on my 2019 TRD ORP followed instructions in the box and after reading everything here (THANKS!) the only issue I had and forgive me if I missed this but in step 18 reinstalling the Lower Airbox on that exact same bolt in the picture it was now longer and left a space so I used 3 3/8″ (M10) grade 5 flat washers to fill the space and get the proper torque. Happy to provide pictures. Thanks again really enjoying the new setup.

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