DIY: Secondary Air Filter Removal

Seconded on the Fuelly recommendation, btw. Easy to use and fast.

I just removed the secondary air filter on the new taco, just like I did in Feb of 2010 on the old one. Similar responsiveness increase and more power. I'm gonna guess it will be a similar MPG increase as well...the old one was roughly 1.3 MPG better.

In 2.5 years I put over 55K miles on that taco. 1.3MPG adds up to some nice cash on a long enough timeline.

 

Just removed the SAF and the advice I can give to anyone with the 4.0 V6 is don't waste your time. It did absolutely nothing. Drove the truck just before removing it and just after and I found no difference in sound or power. It's really not surprising because the filter is almost paper thin (about 1/4 in thick) so there's probably not too much restriction there.

If you're gonna lose sleep at night because you didn't at least give it a try and see for yourself, a hammer and a small chisel will pop the rivets right off with no effort.

As for my 06 taco at NorCal sea level, it was a waste of time. Hope this helps.

 

I don't think charcoal does anything after 3 years. Charcoal doesn't keep absorbing stuff forever. Its like on water filters.... it needs to be replaced after a few months. I don't get the point of the charcoal filter. I've got 120k miles... that charcoal is long gone and only causing more crap the air needs to go through before reaching the engine. Yankig it tonight

 

Its an emmissions thing. I've never seen it done this way..
Im with u on this charcoal filter, I would think you would have to replace it after so many miles.
You would have to replace the entire resonator box to replace the charcoal filter.
I took mine out .

 

The filter captures hydrocarbons that backflow from the intake after shutdown.
On the next restart, the fresh intake charge draws them back into the engine.

It's not like a charcoal filter than is purifying drinking water.

It's no different than the charcoal canister in the evap system.
The system absorbs fuel vapors from the tank, and at some point during running on high vacuum, the system opens the evap purge valve, which purges the system with fresh air and draws the fuel vapors into the intake.

 

why don't they make a filter on the crankcase breather hose that dumps right in before the TB? It makes the TB plate gooey..

I noticed that the intake resonator box is made with a rubber boot on the inside.
On my which is an 2010 4.0 there is rubber on the inside of the box, if you take the box off the engine and put your hand in the hole where the TB goes you will find
there is a resonate chamber made with rubber.. It kinda blew me a way... and the other thing is... the engineering they put into the whole intake system ... guess ya have to read it to understand what I'm getting at..

 

The purpose of the chambered intake (with rubber inside) is to act as a muffler.
It's all EPA noise pollution control equipment.

And yes, the stock intake is quite well designed. Unless you're running a supercharged 4.0, the stock intake will flow more air than any 2.7 or 4.0 will ever need, and the stock paper filter is going to filter far better than ANY aftermarket washable filter.

 

And is it not true the resonate chamber is part of the intake tuning? Its all about the pulse that comes back up..
I find it interesting that toyota has tried to tune this pulse for various rpm levels to get the max power of that rpm band.

If your wondering where im getting this from, i read about the 4.0L specs that are posted here(somewhere..forget) in one of the threads.

I have found that replacing the stock air filter with an AFE dry filter, I lose my bottom end torque.. Have you noticed this too..?
I'm hope i don't lose more torque off the bottom end by putting a exhaust cat-back on.
I'm thinking of putting either a Gibson or a TRD system on..
I'm not familiar with how the TRD exhaust is engineered on the inside of the muffler.
I know that the Gibson is chambered and baffled muffler with no packing.. Gibson works well for a normal vehicle at normal rpm and speed ranges.

I am digging for more info on the TRD system..
Aero Turbine is another exhaust that is interesting system too. I do understand how that works, but weary it may a bit loud in the cab.

 

MAN i hope not! almost ready to pull the trigger on one. I've got 108k miles on my truck and i'm only on my 3rd air filter lol. (stock and then replaced it twice) I should change it more often.

 

Cutting that filter out was probably the best thing I've done.

my car used to crank a lot longer before on startup...
my truck also used to hum and vibrate slightly before shifting into the next gear. Seems like there is SLIGHTLY better throttle response. nothing to brag about on performance gains.

I really like that it starts right up and doesnt hum before shifting. =) time to cut my brothers out.

 

Has anyone had any problems by taking the secondary filter out I want to but worried it would mess up the engine or something...I have a 2011 Tacoma with a k&n drop in filter..

 

I really wana take my secondary filter out but I don't want to mess up anything..so should i or shouldn't I.. I have a 2011 Toyota Tacoma 4.0 v6

 

As long as you don't get any plastic or dirt into the intake, it won't hurt anything. Just completely separate the airbox from the engine before any hacking.
Especially on the V6, it likely won't help anything.

The biggest "risk" is if your state (or the state that a future owner lives in) has smog testing, a knowledgeable, or particularly "picky" inspector may fail the truck if the secondary is not in place.

I removed mine from my 2.7, saw no difference in performance or MPG, and am fully willing to purchase another airbox lid with a new secondary if I fail smog.

 

Im really thinking that cuting the second filter out is a
Bunch of hype.
If ya want more throttle response shift down to 4 for u auto tacos, it fun
Thes the rpm up higher so ur higher on the pipe if u get that term
More revs put u in the power-band and Make more power faster.
With more rpms ,Your engine is pulling in more air and Yes more fuel.
But Its power ya wanted right?
That mass air flow is set up or calibarted for the hydrocarbon screen to be There
So when you delete the hydrocarbon screen it changes the the cal on the maf
By letting more air pass the maf sensor u change the air/fuel ratio so that Its leaner to the point
It may Make better fuel milage crusing down the road with no engine load, but once u need power on the top end it leans out and ya got nothing may be an ses light.

Our maf sensor is very sensitive , so any changes u do to the air intake is going to affect
The air fuel ratio and the power the engine makes .
Our 4.0L engines are more complex than u think.
With the vvi cams and a vr intake mainifold , the intake mainifold is making the most power at
Whatever rpm .
All this info is in that pdf file some one posted about the 4.0 1gr-fe engine.

So in all truth i wish i never cut hydrocarbon filter out
I get the best response form the engine when i have the stock filter in.
And the best fuel milage.

Good luck after all Its ur truck ,do what the fuck u want with it.

 

You a grown ass man! Do as you please! I see it like this. It ain't going to do no harm removing it and it ain't going to do no good either. It probably helped filter out some of the stuff that got past the primary filter, but with 110k miles that short was dirty so I cut it out. Car arts better and less hum before shifting gears.

 

If our mass AF sensors are so high tech they should compensate for the difference. My truck runs rich (black soot and goo on fender) so I figure this helps.

 

Really u would think it would be able to recalculate for the extra cfms coming through. But I don't think yota gave much leeway on under or over amounts cfm flow. Is this correct thinking? Someone's gota know the specs on the MAF flow tollerations.

My thinking is that , the problem may be more in the atmospheric fuel pressure regulator, at least when it comes to a full CAI. That resonator box plays a part in getting the right amount of air pressure to acuate the fpr diaphram to close the check valve to keep the fuel on the rail during open loop.
So I'm thinkin this why u may get a lean code in bank one , possibly.. during closed loop the ecm may just over compensate and get richer.

Well its like this ...computers...cant live withem and ya surely would be damned with outem

 

I ant going to do it thanks for everyone's input

 

Nah, I remember a simpler time without computers. It wasn't all damnation and shit. You'd be alright. It's called reverse adaptation.

 

I'd love to turn back the clock ..