It just seems absurd to pay $300 for something you can make yourself. I finally took the jump and also made a custom SRI. I'm not the first to do it although I like to believe I was one of the first to suggest the idea of cutting out the MAF tube to do so - since last summer. I grew some cajones and did it without buying a back up intake lid either.

Neither FitFreak nor myself is responsible if you cause any damage to your vehicle or yourself in following these steps. Do so at your own risk.


First, Let's buy Some Overpriced Parts:



Pick out a 3" or 2.5" filter of your choice. I went with the 3". Keep in mind you don't have alot of room. The filter pictured is the largest possible to fit as I STRUGGLED to get it in. You will also need a coupler from the filter to the MAF tube which is 2" in diameter when cut down. I however did not realize this yet and purchased a 3" to 2.5" coupler. Instead, purchase a 3" to 2" coupler if you bought a 3" filter (this coupler is NOT common) or 2.5" to 2" coupler if you bought a 2.5" filter (this coupler however is also NOT common). Then you just need a piece of 3" pipe (or 2.5" if you bought a 2.5" filter) to connect the coupler to the filter.

Also purchase a 2.5" to 2.5" coupler if you can find one. I couldn't find one but it is not mandatory and may make the assembly too large to fit.

Don't forget the breather filter!

And of course screw hose clamps:


Alright, We need to get that stock airbox out:


Remove the 2 (10mm) bolts holding the airbox in and remove the MAF sensor connector and cable retaining clip here:

There's one bolt pictured here on the bottom left. The other one is on the right of the box closer to the bottom and near the battery. Remove both.


Now loosen the retaining ring around the rubber coupling that connects to the throttle body with a phillips screw driver. Pictured center here:


Hard to see but you will know what it is as soon as you get in there. Once it's good and loose rock the air box off the throttle body.

Next pull off the final part attached to the stock air box, the breather tube. It's just a matter of giving it a good tug and it will come out.

Now twist the air box a little and work it out of the engine bay. It is possible to do without removing the battery but if all else fails, yank the battery out as it can be tough.

Next we need a rubber coupler out of the stock airbox if you didn't buy a 2.5 to 2.5 coupler.

This one:



save it for later.


Next take off the lid from the stock airbox that has the MAF in it (above the filter)

Remove the MAF:

Pictured right. You do not need to remove the coupling to the left.



Now it's time for the point of no return...


Start cutting away the stock airbox from the MAF tube. DO NOT SCREW UP HERE! TAKE YOUR TIME! FROM THIS POINT UNTIL YOU ARE DONE YOU DO NOT HAVE A RUNNING CAR! Work in sections and do not cut into the MAF tube no matter what. Especially if you didn't buy a back up lid.


^One cut in



Several more cuts in.


Once you get near the end just cut away at any last small pieces with a fine cutting instrument. Finally use a metal file and wire brush to clean up any rough edges and makes sure no plastic shavings are left inside by blowing it out with an air compressor.

When you are done it will look like the middle piece here:





Paint it to cover up scuff marks or leave it as is. Not much of it will be exposed.


Great, now you have the most important part of all, a mounting place for the MAF that will ACCURATELY measure air flow.

Last step before assembly is to take your 3" pipe (or 2.5" if you have a 2.5" filter) and cut it down to a length of about 2" - 2.5" That's just long enough to fit inside both the coupler and filter.

Let's assemble the couplers:

I need a tan winter has been long

So that is the completed coupler assembly. From furthest to closest:

1. The rubber coupler we pulled from the air box (the small straight one) The side with a small lip that has 4 'dashes' cut out (slightly wider inside) is connected to the MAF tube. The side with a half lip (slightly narrower inside) is positioned to be put on the throttle body to ensure a tight fit. You will need a screw hose clamp to keep it on the MAF and another one for later to hold it on to the throttle body too.

2. The MAF tube we cut out. Make sure you orient it correctly. The end with the ridge/circle around it goes towards the engine. The end you had to do the most cutting on goes towards the filter. If you bought a 2.5" to 3" coupler like me you will discover it does not fit on the MAF tube where the flair used to be that you cut off. That's okay. Wrap it TIGHTLY with vinyl electrical tape until you get a very tight 2.5" diameter.

3. Your coupler to the air filter. Tighten it EXTREMELY tight and check for leaks if you had to do the vinyl tape trick for now. It will hold (as the tape will by its very nature fill in any holes) but it must be tight. If you bought the right size (2" to 3'" or to 2.5") then just slip it on.

4. A 3" tube (or 2.5" if thats the size of your filter) to connect the coupler to the filter. Cut it just long enough to connect the filter and coupler, no extra space between the coupler and filter (unless you bought a very small filter)

Now add the filter and admire your work:



Alright, you are ready to try and get it installed...

...
...
...

GOOD LUCK!!! It's a SERIOUSLY TIGHT FIT. I had to push the filter (without tearing it) into the space under the break fluid resevoir as far to the right as it would possibly go. Then I loosened all of the hose clamps so the joints could flex and worked the rubber coupler unto the throttle body and secured it tightly with a hose clamp. Tighten everything back up. No need to add brackets in my setup, the filter isn't going anywhere. If you are having difficulty make sure your assemby is as short as possible.

Don't forget to reinstall the MAF sensor and put on the breather filter.

Completed:




It fits in very deep back there. Very safe from water but in perfect position for the cold air duct and plenty far from the engine.


Impressions,

Perfect. Not much additional noise under relaxed driving conditions. A deeper stronger 'growl' under hard acceleration and as others have said, you actually hear i-vtec kick in yo at 5,300 rpms. Not louder like a fart can muffler, louder like a deeper stronger engine note when you punch the gas. The rev limiter sounds awesome with this on too. As for power... Who knows? Should be the same as any other Intake if not better (do you really think the companies out there have a fluid dynamics engineer design their intakes? If so I've got a bridge to sell you)

Have fun out there Make a heatshield if you get bored after this.

I would record the sound of the engine now but the car is in the shop for repairs after that rear-end accident.

 

Wow, it looks clean and professional. I don't know why, but I love the look with the breather filter. Someone sticky this DIY mod! If I didn't have a PRM already, I'd be cutting up my stock air box right now.

 

very nice!

 

Looks like a PRM but.....worse! Cool!

 

Looks just like mine!!!

Nice DIY! I was too excited to take pictures when I installed mine...lol.
Thanks for taking the time to take pics and give the step by step.

If anybody is too scared to cut their stock MAF box. Just order an extra like I did so you can keep your complete stock air box...just in case.

Here is all you need to cut the MAF tube out.
The part number is: 17210-RB0-000

$18.85 at Bernardiparts

Now lets sticky this baby!

 

I like your style.. It looks real nice. I'm interested to see if you pull a P0171 CEL shortly. I have a similar cheap intake that I had to remove due to the code and could never get the fuel trims with in range. Maybe the small filter is the key instead of tapping in to the intake for the PCV.

 

No code for me (exact same set up). I've had it on for 4 days and 300 miles and works great.
Also on a side note I drove in the rain for the past 3 days no water issues at all. Checked the filter last night and its still bone dry.

 

Awesome! Definitely on.my to do lidt

 

Here are some more pictures for added reference.

Old intake box...


New intake...

 

Wow looks good after I get some money I'm gonna buy another aurbox and all the stuff to do it but first I need to get my underbody kit built and finished

 

After reading it again I think the problem is the diameter of the tube where the MAF sits. You say that it is 2" where mine measures 2 1/2" which may cause the MAF to not read properly. It is seeing slower air but it is more mass causing a lean condition. Also the location of the sensor is a tad off due to the extra area. Sounds good. I will make a 2" insert to test my theory.
Thanks for this post.

 

nice job luv all diy stuffs.

do u think adding a cold air intake hose from the front bumper to the filter helps in anyway ?

 

ah cool, it looks like one of those mustang ram intake systems where you reuse the old MAF. except here you had to cut that sucker out.

i wish i seen this sooner, iam one of the ones that spent 250+ for an intake! but i wasn't patient enough for a DIY to be out.

 

OK as a relative noob I gotta ask, what benefits have you noticed since completing this mod?

 

He noticed a great sense of accomplishment Oh and the fact that there is a deeper growl.
+1
Great diy.I will be ordering an extra maf tube just because I am a rusher. Can you post a video?

 

1) Deeper engine note.

2) Added power. I especially feel it in 3rd gear. Pulls harder 4K rpm and up.

here is K&N dyno from pretty much the exact same design.
http://www.knfilters.com/dynocharts/69-1017_dyno.pdf

 

thats a really good DIY, id be nervous doing that cutting too

 

awesome writeup. thanks for the step by step (w/pictures) diy.
also gotta thank k20a298ek also for being one of the guinea pigs.
wish i could start on my setup but im still awaiting cflhonda to send me my lid. [waah] anybody heard from them? im about to cancel my order cuz im not getting any confirmation from them receiving my order or them ever sending it out. [/waah]

 

Lol, thanks all. No CEL yet. I'll do a video once the car is back from the shop. Still being fixed from the 16 yr old kid driving his mom's Lexus that rear ended me. I did a baseline video too already.

 

Hey, watch this video, it will explain their issue. Episode #179 - Honda Viewer Questions Vol. 33. I don't know if the link works... stupid phone.. (: If it doesn't search it up on youtube.