DIY: Secondary Air Filter Removal

Okay, disclaimer first...

I have no proof that this modification will not do harm to your engine. I have no proof that this modification gives any substantial gains in horsepower, torque, or fuel economy. I have no proof that I have no proof.

That being said, my thinking was: the more that is in the way - the more restriction you have.

From my understanding the secondary air filter in the Tacomas is a charcoal filter to reduce vapor emissions from a freshly shut-off engine. This makes sense to me. It is a charcoal filter. It just doesn't seem to do much else but cause air restriction. So, here is how I took mine out.

Please pardon my filthy truck.

NOTE: This is for 2ND GENERATION TACOMAS ONLY! This section of the tutorial is on a 2.7L inline 4 cylinder engine. For additional pictures showing the 4.0L V6 filter removal CLICK HERE.

You will need:

1) Flat Blade Screwdriver

2) 9/64 Drill Bit

3) Electric Drill

4) 6" x 6" piece of Aluminum Foil

The easiest thing for me to do was remove the upper air box assembly and take it inside.

To do this you need to unscrew the bolt clamp on the intake hose, and you will need to remove the plug to the MAF (Mass Air Flow) sensor. The MAF plug also has a clamp that is mounted to the upper air box. You can pry it out gently with the screwdriver.


Once I removed the upper assembly, I used the aluminum foil to cover the intake tube.

THIS IS IMPORTANT!

The air filter prevents dirt from getting into and scoring your engine (very bad). Without the assembly and filter any thing smaller than 2" can get in there. So, cover it up and protect your investment!



Next you will want to use your drill and bit to drill out the 6 plastic rivets that keep the secondary filter in place. BE CAREFUL NOT TO DRILL TOO FAR!!! You don't want to go to the dealership to ask for a new airbox - it will ruin your weekend.



Once you have the rivets drilled out, you can use the screwdriver to pry out the filter. Once the filter is out you can see that there really isn't much to it.

AGAIN: TO PROTECT YOUR INVESTMENT - MAKE SURE THAT THE AIRBOX IS CLEAN OF DEBRIS AND PLASTIC SHAVINGS BEFORE REINSTALLING!!! THIS IS A MESSY PROCESS AND SHAVINGS WILL BE EVERYWHERE!




That's it! Put it all back together (minus the secondary filter of course), and you are good to go!

Enjoy!

 

Okay - from what I have read about 4.0L V6 owners who have done this, they do not see very much improvement in power or efficiency.

On my 2.7L I4, I actually noticed a big difference in power. I pulled over on the side of the road just to make sure that I put the airbox all the way back together (or put the filter in). Everything was fine! It really made a big difference! I am going to have to see what kind of mileage I get out of it.

I will let you guys know how it goes!

 

UPDATE: This is not recommended if you are in California. Depending on how strict your local inspection office/shop is, they may check to make sure that this filter is place. One of my friends got in trouble for doing this on his FJ Cruiser.

 

In Ca. we don't have regular inspections. No smog inspection for 5 years on a new truck before you have to get another unless you sell it.
Would like to see more inspections but that would discriminate against our illegal visitors from the south of us.

 

Yeah, I think he got his FJ used. it is an 06', I think. He did a bunch of modifications before he went and got it registered. Gotta love "paper plates".

 

So did you notice any change in fuel mileage?
I'm thinking about doing this.

 

By law the seller is responsible for smogging it not the byer but most do a gentlemans agreement. He must have got it private party not a dealer?

 

i did mine back about 7 or 8 months ago! mines the v6, cant really tell a difference as far as gas mileage, but ive got to think that it has to breathe better now, since there is no restriction from it. i mean, just check out how thick that filter is!! some people will argue this, but to me.....guaranteed to breathe better with out this emissions filter!!!

 

I have been home sick (aka - not driving much). I have only gone 55 miles on it (work and back) since the mod.

I think he got it from a dealership. I will have to ask him next time I see him...

That's what I hear - that it doesn't make too much of a difference on the V6. There is definitely a difference in the 2.7L.

 

This is definitely helping my mileage. I got over 400 miles out of this tank this week, and I didn't even fill it all the way up last time I got fuel (I was outta cash).

I filled up last night. I will let you know what I get out of this tank (have to drive to Houston tomorrow).

Hey, moderator, THANKS FOR MAKING THIS A STICKY!

 

That does it. Mine is coming out!

 

Its easy. Just make sure that you have all the plastic debris cleaned out before you put it all together.

 

Its out! Yeah I didn't expect it to be hard. It was simple. I donno I don't really feel any difference. I'll check the mileage and see if there is.

 

The difference is really at the higher RPM. I have gotten about 1/2 MPG better mileage, but I have been heavy footing it in heavy traffic. I am hoping that it will be better this week as I am driving to and from work. I will also be receiving an AFE drop-in air filter on Tuesday, so... we shall see.

 

Ok, I just ran through 3/4 of a tank and I had to report mileage since I am dropping a AFE high flow filter in this morning (the UPS Santa dropped it off in the middle of the night )...
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On the first tank I got about 24 MPG, but that was with a bunch of heavy footing it and some serious sitting in traffic.

On the second tank I got 26 MPG. That is pretty good considering my average highway before was 25.
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Now let's see how the AFE filter does. I admit I am a bit scared. I held the AFE filter up in front of a light and you can see straight through the thing. I had K&Ns like this, but this one is going in my baby.

Driving into work this morning - I did notice that my truck no longer has a hard time maintaining 80 MPH on a hill. I just kept the pedal steady and away we went.

 

I averaged 26 MPG over the weekend. 300 miles of highway driving and about 50 miles of "in the village" driving as we explored Kerrville, TX. The Tacoma definitely is doing better on the high end of tachometer.

 

Ok, this is a first...

I finally hit the EPA estimated 28 MPG driving from San Antonio to Giddings and back. 75 MPH w/ cruise on, no heavy footing, AC on, in the rain. Mods are AFE drop in filter and Secondary filter removed.

 

is that a k&n box? looks like the same box i pulled of a friends superduty

 

Nope - that is the OEM Toyota Intake box off the 2.7L 4 cylinder engine. It is fairly massive though. After taking a good look at it, I decided that it wasn't the big cause of restriction - the filters were.

 

yeah... that thing is pretty massive.. the 07s are tiny, well the nose of the intake i guess towards the engine its a little bigger..