Removing the "secondary filter" aka charcoal filter from the airbox.

Are many of you removing the secondary filter? I did this on my 2007 Tacoma, but not sure about doing it in the new one.
What are the Pors and Cons of it?

 

+1 hp

 

When I upgraded to a TRD CAI (cold air intake), I tried removing the charcoal filter from the OEM box. Didn't feel or notice a difference with it on or off so just left it on the TRD version.

 

...just ask yourself is a miniscule gain in less-restricted airflow which the ECU still calculates air:fuel ratios while not reducing as much air particulates from entering your engine something you truly prefer? Cleaner vs. (Placebo effect) "Gains"...

 

I'm all for getting rid of unnecessary elements that affect performance, but personally, I think that filter does more good than harm.

 

If you change your air filter regularly there really won’t be any cons.
If you never change your air filter, or use crappy filters, there might be a “small” possibility that many many years down the road it can restrict air flow.

I vote leave it in there. It’s really not hurting anything.

 

Removed mine with hopes that it was faulty or clogged and might possibly improve my fuel mileage......it didn’t change a thing....

 

I got rid of mine when I installed my supercharger. Not for more airflow, but because it’s one less barrier for the sound of the supercharger to get muffled by.

You will get a non-noticeable amount more airflow by removing it. There is zero harm to removing it other than possible smells.

The purpose of that filter is to block crankcase fumes (from the passenger valve cover vent) and other hydrocarbon smells from exiting the intake when the car is off. So it’s a filter for air leaving the intake. Your primary filter does actual filtering.

I have noticed no increase in smell, but if you start to smell a hint of oil or fuel in the garage after you remove it that is why.

 

Lexus V8 F cars (IS F, RC F, ETC) have an air box with a vertical filter. The upper half lacks the charcoal filter, likely for noise, but could play into resonance, throttle response, or flow.

 

it's a very non-restrictive filter strictly for emissions purposes. I wouldn't bother removing it. Noone has ever mentioned any change in performance after removal. I do wonder how long it's actually effective for, as even the best charcoal filters are usually only effective for a year or two tops...

 

Thanks guys. Guess i will leave it alone.

 

My '06 4Runner with the 4.7 (285k on the clock) threw a code for months (can't remember the codes, but basically it was running too rich). Tried everything...new air filter, new MAF sensor, new spark plugs, new gas cap. It just got worse and worse, to the point where it ran like crap sometimes and I didn't want to drive it. Took the charcoal filter out and it was like a new vehicle. Ran better than I can ever remember and I believe the mileage even went up a bit. I would have never believed it could be the issue if I hadn't lived it.

 

If you look up the difference in flow between a dirty air filter and a clean air filter it’s such a small difference that removing this is pointless and is not going to do anything. If the trd intake barely does anything at all removing this won’t help.

 

Wait, so you removed something and then years later, now ask if there are pros and cons? Why did you do it to begin with then?

 

I'm pretty sure that this thing doesn't filter particulates. It is for absorbing gas fumes that come back thru the intake when the engine is shut off. When it is running it doesn't do anything (other than restrict airflow in my case). Maybe mine, because of the high mileage, was more restrictive than when new or fairly new.

 

Surprised it didn't throw an air/maf code.

 

Not the answer I would expect from MaGuyver.
Kinda disappointed if I'm honest.

 

I think the code was P0177, "system too rich" but it's been a while. It was both cats/banks too.

 

don't bother, it doesn't do anything worth the effort of removing it that I'm aware of

 

This is correct. It absorbs fumes. Doesn't stop dirt. The next time the truck is started, it pulls the fumes out of the charcoal, "refreshing" the media and "saving" the environment. The charcoal canister on the gas tank does the same thing but on bigger scale. Both useless.