Air filter box mod
mattbeeezy - I'm wondering if this mod might enhance the exhaust note in conjunction with that Oliver guy's Exhaust Vent product. You may know.
Do you have any comment? Did you notice any audible difference before / after the carbon filter deletion (CFD
).
I'm about to do my engine filters, and while I'm in there, I may yank the carbon part. If I remember right, the carbon portion is a second portion. If I have any issues, they'll go back in.
Jason
Do you have any comment? Did you notice any audible difference before / after the carbon filter deletion (CFD
).I'm about to do my engine filters, and while I'm in there, I may yank the carbon part. If I remember right, the carbon portion is a second portion. If I have any issues, they'll go back in.
Jason
Honestly, It could have. That carbon potion takes a good amount of air filter box up top. You can hear a difference at WOT and my butt dyno feels a little difference too but could be all in my head since I've been on the gassing more after putting your exhaust vents on lol. I just bought Tom's super ram air filters, I should be doing a review on those shortly. If it gets louder we have a winner.
Thread Starter
Driver School Candidate
Joined: Jan 2012
Posts: 20
Likes: 8
From: WI
Update a year later
I did this mod over a year ago on my LS and have not had one issue. I am getting 28mpg on hwy. if you add K&N and get errors that is the oil getting on mass airflow sensor. Clean and put paper back in.
I do notice more intake noise especially on my GX but not difference on exhaust (OEM) on both models.
There is not going to be any big improvement on power but better response on WOT. Main improvement is fuel mileage. Again if you want more power spend $$$$$. If you want free little improvement try this. Between my friend and myself of a total of 17 vehicles, not one has had an issue. These include RAV4, tundra, Tacoma, 4Runner, scion models, camry, Avalon, all Lexus, and yes you hippies even the Prius.
As for K&N battles; use this filter for off road, you can clean after every adventure, much cheaper than paper. If you are doing this for power don't waste your time with K&N just do this mod. It is simple and safe.
Non US models, correct you do not have this carbon filter. As far as I know only US. Lots of tree huggers over here. Not saying it's bad just saying.
2007 GX filter has been out and using K&N for over 5 years: not one issue and passes WI emission tests.
2009 LS mod with paper Wicks air filters for 16 months and no issues and has passed all WI emissions tests.
I do notice more intake noise especially on my GX but not difference on exhaust (OEM) on both models.
There is not going to be any big improvement on power but better response on WOT. Main improvement is fuel mileage. Again if you want more power spend $$$$$. If you want free little improvement try this. Between my friend and myself of a total of 17 vehicles, not one has had an issue. These include RAV4, tundra, Tacoma, 4Runner, scion models, camry, Avalon, all Lexus, and yes you hippies even the Prius.
As for K&N battles; use this filter for off road, you can clean after every adventure, much cheaper than paper. If you are doing this for power don't waste your time with K&N just do this mod. It is simple and safe.
Non US models, correct you do not have this carbon filter. As far as I know only US. Lots of tree huggers over here. Not saying it's bad just saying.
2007 GX filter has been out and using K&N for over 5 years: not one issue and passes WI emission tests.
2009 LS mod with paper Wicks air filters for 16 months and no issues and has passed all WI emissions tests.
Last edited by jafoo; Mar 14, 2017 at 10:47 AM. Reason: typo
Rookie
Joined: Dec 2013
Posts: 35
Likes: 4
From: Florida
There was a study by the EPA to measure the effects of restricted air flow caused by a clogged engine filter: https://www.fueleconomy.gov/feg/pdfs...02_26_2009.pdf
A quick summery was that restricted air flow had minimal effect on MPG (<2%) but had a more noticeable effect on performance, as measured by acceleration times (7-11% improvement).
Again these numbers assume a worst-case airflow restriction - which I would find hard to believe would be the case of the Lexus charcoal filters. But either way, better performance along with a (minor) increase in MPG - seams like a no-brainier to me to remove the filters.
Ironically I had replaced my air filters and cleaned the throttle body just a week ago - and noticed the charcoal filters for the first time. Next weekend they will be removed!
A quick summery was that restricted air flow had minimal effect on MPG (<2%) but had a more noticeable effect on performance, as measured by acceleration times (7-11% improvement).
Again these numbers assume a worst-case airflow restriction - which I would find hard to believe would be the case of the Lexus charcoal filters. But either way, better performance along with a (minor) increase in MPG - seams like a no-brainier to me to remove the filters.
Ironically I had replaced my air filters and cleaned the throttle body just a week ago - and noticed the charcoal filters for the first time. Next weekend they will be removed!
Lexus Fanatic
Joined: Jan 2014
Posts: 5,371
Likes: 526
From: BC Canada
Me too. After a frightening oil analysis done, I stopped using them about 15 years ago. My oil analysis noted high level of Silica (sand). Yes the filter will provide more air, but as a result, also lets in more contaminants. You can't have it both ways. For what benefit? Nicer sound? It certainly doesn't give more power - many tests, reviews and dynos have proven this. The fact that K&N have a dedicated section of their website addressing MAF and other concerns, speaks to there being issues. Even IF a K&N provided a 10hp increase, you would not notice it in a 5000 lb car. If you do decide to be lured by K&N claims, be sure to do at least one oil analysis after an oil change. You might be disappointed by the results.
Former Sponsor
Joined: Jun 2016
Posts: 1,002
Likes: 207
From: Georgia
I just changed my engine filters and cabin filter. While I had things apart, I sealed the outlet of the cover with my mouth and fingers and blew backward across the carbon filters. There was no pressure, as if it weren't there. But, my "flow rate" is way lower than the car's flow rates. I'm going to see if I can't find a way to remove them and be able to reinstall them. They seem to be sonic welded (I think) in place. I would be interested in the sound difference, as I have my doubts they really do much. But if I don't notice much difference in sound, I want to be able to put them back in.
Jason
Jason
Rookie
Joined: Dec 2013
Posts: 35
Likes: 4
From: Florida
I removed the charcoal filters this weekend. The filter material itself is very course and contains what looks like small blocks of charcoal arranged in a checker-board-like fashion - although there is much more space between the small charcoal blocks. The charcoal filter fabric is much more coarser (larger openings) than the replaceable engine air filter, so I am not sure how it could become "clogged" (maybe the oil in a K&N filter can foul the filter?). But since the air must pass through the filter, I assume that it adds some level of air restrictions, but I would be surprised if would be noticeable, and then probably only when WOT.
Pole Position
Joined: Jun 2018
Posts: 2,415
Likes: 217
From: Ontario
I removed the filter yesterday, such an old car it must be dirty AF since it is so dusty here anyways... today.. check egine VSC PCS was in limp mode. I cleaned the MAF sensors.. with contact cleaner.... I cannot get CRC here but I do not think contact cleaner meant for electronic stuff is going to make a difference...
So throttle body I could not remove because I did not want to tear the rubber hoses at the bottom, in case it tears I have no hoses on hand to replace and will have no car to drive... so i just cleaned it there and replaced it...
I was going to clean the IAC.. idle air control but I cannot figure out where it is... I want to change the PCV valve but if i have to take off the manifold... I cannot do it on my own..i live in an apartment and it would be too many parts to take off... and too many cables and tubes..
So throttle body I could not remove because I did not want to tear the rubber hoses at the bottom, in case it tears I have no hoses on hand to replace and will have no car to drive... so i just cleaned it there and replaced it...
I was going to clean the IAC.. idle air control but I cannot figure out where it is... I want to change the PCV valve but if i have to take off the manifold... I cannot do it on my own..i live in an apartment and it would be too many parts to take off... and too many cables and tubes..
Pit Crew
Joined: Dec 2017
Posts: 158
Likes: 19
From: NY
I removed the filter yesterday, such an old car it must be dirty AF since it is so dusty here anyways... today.. check egine VSC PCS was in limp mode. I cleaned the MAF sensors.. with contact cleaner.... I cannot get CRC here but I do not think contact cleaner meant for electronic stuff is going to make a difference...
So throttle body I could not remove because I did not want to tear the rubber hoses at the bottom, in case it tears I have no hoses on hand to replace and will have no car to drive... so i just cleaned it there and replaced it...
I was going to clean the IAC.. idle air control but I cannot figure out where it is... I want to change the PCV valve but if i have to take off the manifold... I cannot do it on my own..i live in an apartment and it would be too many parts to take off... and too many cables and tubes..
So throttle body I could not remove because I did not want to tear the rubber hoses at the bottom, in case it tears I have no hoses on hand to replace and will have no car to drive... so i just cleaned it there and replaced it...
I was going to clean the IAC.. idle air control but I cannot figure out where it is... I want to change the PCV valve but if i have to take off the manifold... I cannot do it on my own..i live in an apartment and it would be too many parts to take off... and too many cables and tubes..
I like the general idea of the mod once I am out of warranty but don’t want to risk tripping codes to be honest.
Pole Position
Joined: Jun 2018
Posts: 2,415
Likes: 217
From: Ontario
So what was the outcome here? Did removing those charcoal filters directly result in codes? Did you have to reinstall those filters as a solution. If that was the case I am not sure why anyone would want to risk this mod..
I like the general idea of the mod once I am out of warranty but don’t want to risk tripping codes to be honest.
I like the general idea of the mod once I am out of warranty but don’t want to risk tripping codes to be honest.
Instructor
Joined: Jan 2014
Posts: 778
Likes: 130
From: texas
My GX did get about 1mpg but when I have mud tires on and my heavy foot hard to talk mpg improvement. Now power, I did add the K&N at the same time but I will say the hp and torque did increase a lot. I noticed this while hill climbing and playing in mud.
My LS I did see about 2-4 mpg on hwy. I do get 28mpg strictly hwy if I drive nice and stay at 70mph. This is hard to do as people usually **** me off and I hit 100 mph to get away from them.
Overall this mod will get air faster into the intake. But remember, the MAF sensor with throttle position controls the amount of air/fuel mixture into the cylinders. This is great for instant power increase and overall easy flow. It is a free mod.
If you want better mpg start with tires. You want HP then expensive mods starting with computer mods but hard to find for these toys.
My LS I did see about 2-4 mpg on hwy. I do get 28mpg strictly hwy if I drive nice and stay at 70mph. This is hard to do as people usually **** me off and I hit 100 mph to get away from them.
Overall this mod will get air faster into the intake. But remember, the MAF sensor with throttle position controls the amount of air/fuel mixture into the cylinders. This is great for instant power increase and overall easy flow. It is a free mod.
If you want better mpg start with tires. You want HP then expensive mods starting with computer mods but hard to find for these toys.
Racer
Joined: Apr 2002
Posts: 1,667
Likes: 210
From: Someplace in CT
I know many people argue about installing a K&N style filter is better than a stock filter. I have no arguments about that of which is better or which is better air flow (air flow being the key subject). K&N are nice, I do have one in my GX470 due to the amount of off-roading I do with it. Just clean and reuse. But before you go too deep thinking about better air flow; look in your air box and you will notice a stock carbon filter on the top unit that is not replaceable. This unit is major air restriction.
I am just giving everyone a tip to try, if you don't like the idea then simply don't do it. I believe this carbon filter is for gas vapors leaking back into the air. I do have emissions by me and all of my vehicles and my friends vehicles we done this on have had no issues from emission tests or engine lights. We have done this on Toyota, Scion, and Lexus vehicles. I have done this on my 2007 GX470 at 79K and now has 138K and never had an issue. My 2009 LS460 is where the pic's are from and did it 6 months ago with no issues. LS is using OEM style filters, GX has K&N. NOTE** if you use K&N careful on the amount of oil so you do not get the MAF sensor full of oil, without this filter you might get excess oil on sensor (I oil and let it set for a few days, dampen off with towel before installing).
Steps: (sorry I was not able to type by pic's)
First pic is the filter on the top air box. Remove from car and set on the bench.
You will find little melted rivets that attach the filter. I used a razor blade and cut the edges off. Take a small flat screw driver and gently pry up. Be cautious so you do not damage the box edge that seals to the bottom box, do not worry about the carbon filter you are removing.
You can now see how much air flow this filter restricts. Now put top box back on, save filter to make you feel better if something happens. Repeat for other air filter box.
I am just giving everyone a tip to try, if you don't like the idea then simply don't do it. I believe this carbon filter is for gas vapors leaking back into the air. I do have emissions by me and all of my vehicles and my friends vehicles we done this on have had no issues from emission tests or engine lights. We have done this on Toyota, Scion, and Lexus vehicles. I have done this on my 2007 GX470 at 79K and now has 138K and never had an issue. My 2009 LS460 is where the pic's are from and did it 6 months ago with no issues. LS is using OEM style filters, GX has K&N. NOTE** if you use K&N careful on the amount of oil so you do not get the MAF sensor full of oil, without this filter you might get excess oil on sensor (I oil and let it set for a few days, dampen off with towel before installing).
Steps: (sorry I was not able to type by pic's)
First pic is the filter on the top air box. Remove from car and set on the bench.
You will find little melted rivets that attach the filter. I used a razor blade and cut the edges off. Take a small flat screw driver and gently pry up. Be cautious so you do not damage the box edge that seals to the bottom box, do not worry about the carbon filter you are removing.
You can now see how much air flow this filter restricts. Now put top box back on, save filter to make you feel better if something happens. Repeat for other air filter box.
I get if you could clean it or replace but, this is not designed to be replaced.
No interest in K & N or a 3rd party filter, just talking about the built in one..
I was thinking about pulling it out but, didn't want to be the first..
Pole Position
Joined: Jun 2018
Posts: 2,415
Likes: 217
From: Ontario
I was always wondering this one, there another filter that CAN NOT be changed. So in the life the car, it will never be cleaned, This could rob HP or mileage.
I get if you could clean it or replace but, this is not designed to be replaced.
No interest in K & N or a 3rd party filter, just talking about the built in one..
I was thinking about pulling it out but, didn't want to be the first..
I get if you could clean it or replace but, this is not designed to be replaced.
No interest in K & N or a 3rd party filter, just talking about the built in one..
I was thinking about pulling it out but, didn't want to be the first..
You can always buy new lids from Lexus but it's expensive X 2. I agree with Stkgator, from looking at the photos of this filter, once removed, there doesn't appear to be much to physically block air or get clogged enough to make any real world difference. A simple vac or compressed air cleaning is all one can do. It's only there to neutralize VOCs. Removal will increase your carbon footprint and defeat emissions control. Fresh "paper" filters is all you need to change regularly.
Maybe one of the members who deleted them would be willing to wash one of them and report back on the results, if water destroyed them, etc.
I suppose that the filter eventually becomes ineffective against VOCs. Worth discussing but not worth losing any sleep over.
Maybe one of the members who deleted them would be willing to wash one of them and report back on the results, if water destroyed them, etc.
I suppose that the filter eventually becomes ineffective against VOCs. Worth discussing but not worth losing any sleep over.
Last edited by swfla; Sep 9, 2021 at 08:39 AM.