DIY: Secondary Air Filter Removal

If the 2-3mpg was actually accurate then your plugs must have been in really bad shape. The K&N has zero effect on mpg.

Well studied, under general non full throttle driving the throttle plate is way more restrictive than the air filter. Air filter isn't a restriction so can't effect fuel use.

http://www.fueleconomy.gov/feg/pdfs/Air_Filter_Effects_02_26_2009.pdf

 

Removed my charcoal filter today using the jhodge83 "grip 'n' rip" method. Tried briefly using a chisel to shave the posts down, decided "f that - I'm not putting the thing back on", got it done in about 5 minutes total. Cleaned the cosmoline crap the dealer had put on the engine plastics off while I was under the hood. Stuff's nasty.

Haven't taken it out for a real drive (just a couple of circles in the intersection moving it from street to driveway and vice-versa). Don't notice a big difference (if any) in sound, but the engine does rev considerably freer. Amazing what a little airflow can do. Held up the charcoal filter, could see a tiny bit of light through it at just the right angles but not much. Obviously not an insignificant restriction.

What did we ever do before the internets?

 

great info.!!! noticeable improvement in output, possibly mileage also.

May I offer a suggestion on removal of 2nd filter?

Rather than drill the rivets, I sliced the filter with a knife (no need to save it!-allowing me access between housing and filter. Same simple knife easily cut plastic rivets!

MUST be done on the bench, for the reasons stated!!

Thanks again to all of you!!!:

 

You could always use some double stick tape to re-install.

 

Did this mod yesterday. I did the rip method. I used a small 90 degree flathead and pryed it enough to get my fingers in there, then just ripped it out. Came out clean with no plastic pieces. Took me all of 3 minutes to get it done. I haven't noticed any power increase, however I have noticed a slight better throttle response. Hope to see if it had any effect on MPG on the next fuel up.

 

It will have zero affect on mpg.

 

Is there a charcoal filter on this model with a 4 cylinder???? Thanks!!!

 

Yes

 

I did this last week. I filled up yesterday mileage improved by .2 miles per gallon. I know... it's not a lot, and hardly definitive on one fillup. But I'll keep tracking my mileage. And it does have better throttle response. That alone is worth "the price of admission".

 

I pulled mine after reading a few posts about the huge changes in performance and economy, even some stating the truck sounded differently. I expected little or no change, but thought I'd try it anyway. Regardless I did some full throttle speed/distance tests before so I could have a good comparison after. I was not surprised by the results. No change in performance, noise, nor MPG. My speed tests were rolling start 20-65MPH acceleration on flat and climbing. I did several back to back runs with and without the secondary, no change. MPG average, no change. Sound, of course, no change. After a few weeks, in case it needed to 'get used to it', I redid the speed tests. Speed dropped just tiny bit, but humidity was up so that's probably it.
Speed tests were done in 80-85 degree weather, full fuel tank, no cargo. The truck is stock with the factory air filter with 31k miles.
It's been repeatedly proven that people's feel of a car will change based on sight, sound, and the knowledge that something's been done to "make it faster" and that will change their opinion of how it's running.
For those who enjoy the fallacy of it being faster, pull it out anyway as there's no real harm as long as you don't screw up in the removal and cleanup process.

 

^^^^^^^^ What he said.

 

OK, first off I have not read all of the replies to this "mod", but the fact that Toyota would put a "permanent" secondary air filter in place, not matter how small is CRAZY. All that I can say is that Toyota is going totally PC in their offerings. It is amazing how they scrimp in some areas and then overkill in other areas (like this). I guess if one area is required by the Fed/State govt. to be installed, they have to save money somewhere...
BTW, I live in CA and will still do this mod and just make sure to leave room for new rivets or screws to reinstall before sale if required.
Thanks for the heads up.
Ken

 

There's your answer to why it's not crazy.

PC? or just following regulations.

 

Wait a minute, this is a "screen" that is the same size as the air filter, but sits between the air filter and the throttle body, right? If that is the case, there is NO way this is a "permanent" filter. They used to use charcoal "canisters" for this purpose in vehicle and I can see them being promoted as "permanent", but not that flimsy charcoal air filter. No matter what, it can still get clogged enough to restrict airflow. It just seems like a really lame "permanent filter" if I am reading this correctly.
Ken

 

Charcoal canister is for fuel vapor from your gas tank and we still have those also, this carbon filter is just for what can vent from the intake after shut off.

My air filter makes sure the carbon filter doesn't get clogged, so yes it is permanent and actually pretty porous since carbon filtration doesn't need to be restrictive.

 

It is not a filter.
It does not get dirty (unless your filter is bad or you've installed an oiled air filter).
It is simply a mesh that contains activated charcoal pellets that absorb any hydrocarbons that backflow from the intake manifold after engine shutdown.

 

OK, got a better idea of the purpose of the "filter", thanks guys.

I realize that whatever is fouling the mesh has to first make it through the filter or backflow from the manifold, but it still seems like the charcoal mesh thingy could still limit airflow, no?
I know this is off topic, but regarding the charcoal canister, does it recover from the top of the fuel tank or is it from the overflow tube where you fill the tank?
Please excuse my ignorance
Thanks again,
Ken

 

Insignificant... as supported by the lack of change in MPG or power observed by those who have removed it (including myself).
Hold it up to your face and blow through it... it's like blowing through a window screen.

Top of the filler neck... there is no overflow tube. If you "top off" your tank and run fuel all the way to the top of the neck, it will flood the canister, resulting in a CEL, running rich as the system attempts to purge the now-damaged canister, and the need to replace the canister (above the rear of the tank, not easy to get to).

 

10-4. Gotcha.

THAT is what I was thinking of. Seems kind of lame that they even bother with the charcoal canister. I used to work at a company called "Vetronix" (since purchased by Bosche) that made the scan-tools for Toyota, Lexus, Nissan, Acura, GM and other manufacturers) and we had a guy that was an ex-Master Mechanic. Anyway, we were talking about the charcoal canister and it seems to be a waste, like a "1-shot deal". If you overfill the tank ONE time, it ruins the charcoal (it can only absorb so much of anything). guess it is the last leg of the coal industry (thanks mr. president).
Ken

 

The purpose of the canister is not to absorb excess fuel. It is not an overflow pipe, and the canister is not there to capture "overflow" fuel.

The canister is working constantly. Like the screen in the air filter housing, it captures fuel vapors exiting the tank vent and prevents them from being released into the atmosphere.
When the engine is started, the ECU opens the purge valve and air is drawn into the intake manifold through the canister. This pulls the captured vapors into the engine.

If your fuel cap is not installed properly, you will get a CEL with a Evap system code... the system is a "closed" system, but since the tank can not be completely sealed unless it were a bladder, the charcoal canister is the filter isolating the fuel in the tank from the outside air.

And activated charcoal is not coal... it has nothing to do with the coal industry. It is more closely related to what you stoke your BBQ with.