Air flow EPA filter thingy

[keylay31]

It's funny how these thread topics seem to come full circle, and I'm sure some of you t4r.org old timers are going to get pissed I brought this up again, but here goes.

I remember about 10 months ago there was a thread (and links to another forum) about taking out that small filter behind the air filter. As I understand it, its only there so the 4runner can pass emissions testing 10-15 years out from now. As i also understand it, it greatly reduces airflow and emissions testing is being phased out.

It's riveted in there, and I'm thinking of taking it out. Anyone who's done this, now that time has passed, have you regretted it? Learned anything new about it? Had an emissions test done?

Basically, is there any reason I shouldn't take it out? Has anyone done a dyno before and after?

 

[greasefingers]

Since the charcoal filter has even less resistance then the stock paper air filter, I do not see the point. BTW the air filter does not restrict flow that you can measure or feel the difference.

How is Colorado not going to test for emissions in the future? Don

 

[Even Steven]

I remember about 10 months ago there was a thread (and links to another forum) about taking out that small filter behind the air filter. As I understand it, its only there so the 4runner can pass emissions testing 10-15 years out from now.



What gives you that idea? If its there now, I'm sure it serves a useful purpose now, not 10-15 years from now. Do you really believe Toyota would go through the trouble and expense of engineering that piece for no other reason than emissions testing in 10-15 years? That doesn't make any sense to me. Add the fact that emissions-based testing is ALWAYS age dependent. In other words, cars on the road today will not be held to the same emissions standards as cars in the future. Just as it would be unreasonable to expect a 1970 Mustang to meet the same emissions standards that a new 2007 model meets.

As i also understand it, it greatly reduces airflow and emissions testing is being phased out.



Again, how do you know it greatly reduces air flow? Some guy on the forum said that? Maybe it doesn't reduce air flow at all.... There's no way to know if there's a power loss associated with it unless someone is willing to do dyno testing, and even then, the results will probably be so insignificant that it won't be measurable on a repeatable scale. As far as emissions testing, the only reason it is being phased out is because newer vehicles are being tested by virtue of their check engine light. If the vehicle's engine light isn't illuminated, then it is assumed that the emissions system is functioning properly and that the vehicle isn't experiencing any emissions system problems.



It's riveted in there, and I'm thinking of taking it out. Anyone who's done this, now that time has passed, have you regretted it? Learned anything new about it? Had an emissions test done?

Basically, is there any reason I shouldn't take it out? Has anyone done a dyno before and after?

I'll tell you why I won't bother taking mine out:

1- No proof that it will give me any extra power or fuel economy.

2- It's there to filter hydrocarbons (unburned fuel) from venting back into the atmosphere. Removing it defeats the purpose of even having it there in the first place.

But hey, that's just me. You can obviously do what you want.....it just doesn't seem like you thought it through...

 

[Even Steven]

How is Colorado not going to test for emissions in the future? Don

 

[SConnors]

Mine's out... for better or worse.

I don't see the point of having it, so it's gone.

Any fuel in the intake would have to get past the intake runners, the throttle body butterfly, 3 feet of intake hose, the general purpose air filter, another foot of air filter housing, and about five cubic feet of internal fender volume before it hits the air. Eve if it made it all the way to the air filter, as soon as I start the engine (daily) the vapour is sucked back into the combustion chamber.

It's not the first time a component of questionable practical effectiveness found it's way into a smog control system.

For the record, mine was not riveted, removing mine resulted in exposure of nipples that would enable replacement should I change my mind.

In the interest of full disclosure, I was once a Master Mechanic and am currently finishing my degree in Mechanical Engineering.

It is generaly true that anything placed in the path of fluid flow results in some resistance. The question each of us should be asking is if the resistance to flow (perhaps too low to affect power) is worth the cost of eliminating a smog preventing component (perhaps with little effect on emissions).

For me, it was a no-brainer... 5 mins and it was out!

Take that smog Nazis!!!

 

[Zmtking]

Just make sure you check the weep hole (if that is what it is) in the air filter housing. I looked at mine the other day when changing my air filter, and noticed that it appears to be on the wrong side. If you really examine the housing it looks like it would drain any moisture towards the front (where the weep hole is) because of the shape. However upon looking at it further I noticed that it actually looks like it drops to the rear. You have to try to look under it to see it. I could be wrong, and haven't really looked at it since, but that's what it appears to be.

 

[keylay31]

Take that smog Nazis!!!

Haha omg.



...What does the weep hole have anything to do with it? Am I missing something?

 

[Even Steven]

Mine's out... for better or worse.

I don't see the point of having it, so it's gone.



You may not see the point of having it, but the engineers who designed the emissions controls system sure did.



Any fuel in the intake would have to get past the intake runners, the throttle body butterfly, 3 feet of intake hose, the general purpose air filter, another foot of air filter housing, and about five cubic feet of internal fender volume before it hits the air. Eve if it made it all the way to the air filter, as soon as I start the engine (daily) the vapour is sucked back into the combustion chamber.



I think you're missing the point. The fuel doesn't have to make it, the fuel vapors do. And you should know that vapors can easily travel through the system and vent into the atmosphere.




It's not the first time a component of questionable practical effectiveness found it's way into a smog control system.



What other component are you talking about? Maybe something on a vehicle when emissions were first becoming mandatory in the 70's that's true, but I think they pretty much have it figured out when it comes to LEVs and ULEVs these days.




In the interest of full disclosure, I was once a Master Mechanic and am currently finishing my degree in Mechanical Engineering.



That's interesting. You and I have a lot in common. I was also an ASE certified Master Tech for a number of years before obtaining my engineering degree.

With your background, I would think that you should see the point of having it in the first place.



It is generaly true that anything placed in the path of fluid flow results in some resistance. The question each of us should be asking is if the resistance to flow (perhaps too low to affect power) is worth the cost of eliminating a smog preventing component (perhaps with little effect on emissions).



Like I said earlier, nobody has proven that its removal will net any HP gain at all. Even if removing it did gain a couple of HP, I would still leave it there because I'd rather have it in place doing its job instead of gaining one or two HP that will not even be a noticeable power gain.



For me, it was a no-brainer... 5 mins and it was out!

Take that smog Nazis!!!

 

[SConnors]

Even Steven,

Lets agree to disagree on this one. You don't see the point of taking it out and I don't see the point of leaving it in.

My truck, my choice.

Did you really think I was speaking of liquid fuel?


Taking out the filter in conjunction with a K&N pannel filter and Mobil 1 oil in the engine, rear dif, and transfer case resulted in a 10% increase in milage (~2mpg) when I take it easy on the freeway. MPG is calculated via the odometer.

Now my truck is still breaking in (5600 miles) so some of the mileage increase could be atributed to that.

Day to day driving seems to be about the same as before the mods, more along the lines of less than 1 MPG better, but I'll take it!

Also, I spent 100 bucks on the filter and oil, so if you look at it from an economic standpoint, it'll take more than a decade to break even with fuel cost at $3.50/gal.

YMMV

Sean

 

[Even Steven]

Even Steven,

Lets agree to disagree on this one. You don't see the point of taking it out and I don't see the point of leaving it in.

My truck, my choice.



Agreed. That's what I said in the beginning of this thread. You (or anyone else) can do whatever you want with your vehicle. I just think it's important to make sure people know the real deal and not spread misinformation. In this case, the misinformation is that it serves no purpose and removing it will provide more power or better fuel economy.



Did you really think I was speaking of liquid fuel?



Yes, by your description, it sure seemed like you were saying that it would be difficult for the fuel to travel so far. But as you know, vapors can easily travel through the system without a problem.





Sean

 

[SConnors]

Dude,

You demand proof and provide none. Your assumptions are questionable at best.

Fuel vapors have a higher molecular weight than air. Traveling through all that inltake legnth and air filter to fresh air would prove extremely dificult as previously posted. The same concept as a sink trap applies. I'd love to see some sort of proof that the vapours travel "easily" through the intake system to fresh air. Talk about misinformation!

How about showing that retaining the filter has emission benifits, other than saying that the engineers "knew what they were doing"... Do you know the engineers in question? Do you know the design criterea and constraints placed on the design?


My empirical data did show a mileage increase. That is not misinformation.

I'm done with this discussion... Banging my head against a wall just serves to frustrate me. You just keep ignoring the data that disputes your theorys, I'm sure you'll go far.

 

[Even Steven]

Dude,

You demand proof and provide none. Your assumptions are questionable at best.



Demand proof about what? That fuel vapors can vent into the atmosphere? That's simple logic. Why do you think EVAP systems have been on cars since the '70s??? That's right, because fuel vapors can easily escape and vent into the atmosphere. You can say whatever you want, but manufacturers didn't go through the trouble of designing these systems and spending the money to put them in vehicles for nothing. No proof required for that!



Fuel vapors have a higher molecular weight than air. Traveling through all that inltake legnth and air filter to fresh air would prove extremely dificult as previously posted. The same concept as a sink trap applies. I'd love to see some sort of proof that the vapours travel "easily" through the intake system to fresh air. Talk about misinformation!

How about showing that retaining the filter has emission benifits, other than saying that the engineers "knew what they were doing"... Do you know the engineers in question? Do you know the design criterea and constraints placed on the design?



What is the molecular weight of fuel vapor? If YOU are demanding facts, then how about providing them instead of blanket statements like that?

FYI, we're talking about EVAPORATIVE emissions here, which is where liquid fuel EVAPORATES into a gas. This occurs more frequently when the temperature of the gasoline rises, such as on top of a hot engine. If you think about it, the filter makes perfect sense exactly where it is located, due to an increased amount of evaporation.




My empirical data did show a mileage increase. That is not misinformation.



Your fuel economy data doesn't prove anything. Too many variables to be worth anything at all.

I can post the same data without changing anything at all on my 4Runner. Things like driving conditions, ambient temps, idling, highway driving, oxygenated fuel, etc... all have an impact on fuel economy.

You have no way of knowing that your statistical "gain" in fuel economy has anything to do at all with the removal of the filter. That's not misinformation.



I'm done with this discussion... Banging my head against a wall just serves to frustrate me. You just keep ignoring the data that disputes your theorys, I'm sure you'll go far.

If you ever post some actual legitimate data, I'll be happy to look at it. What you've posted so far really means nothing at all. Sorry.

 

[keylay31]

Is anyone else enjoying this arguement?:bash:

Each of you have stated your opinion, thanks! But for the last 4 posts, you havent stated anything new. Even steven, u seem to want to be picking a fight. Let the man get his opinion in, and lets get some others too.

I started this thread to get this type of conversation, but lets not flame on the internet :bigok:

Anyone else?

 

[SConnors]

Keylay,

I think the bottom line is that it's completely reversible if you take it out. Give it a shot... If you don't like it pop it back in.

 

[Uneek]

:corn: never had a chance to use it.

State your opinions and move on, to each and his own. If one prefers to run without any filter, so be it. If one wants to run 100 octane racing fuel, let it be.

 

[keylay31]

:corn: never had a chance to use it.

State your opinions and move on, to each and his own. If one prefers to run without any filter, so be it. If one wants to run 100 octane racing fuel, let it be.

Lol. hint hint?

 

[Even Steven]

Is anyone else enjoying this arguement?:bash:

Each of you have stated your opinion, thanks! But for the last 4 posts, you havent stated anything new. Even steven, u seem to want to be picking a fight. Let the man get his opinion in, and lets get some others too.

Not trying to pick a fight at all. If anything, it seems that he got upset with me for wanting to deal with facts.
Read the posts again....I'm not the one who was getting excited here. I honestly don't have a problem with any of this, but I don't really like it when I see misinformation being posted in the forum. If I see something that I think is wrong, then I'll speak up about it. Isn't that a basic strength of a forum like this one?

In any event, I'll say this again for the third time in case you missed it the first two times-- It's your vehicle, so do as you please.