The 2005+ Taco guys have removed the secondary filter with improved performance.

 

Interesting, I did notice the filter is actually restrictive. I put it in front of my home hepa filter and the unit started to strain with the filter there.

After reading your thread, I poked around and I noticed on one of the other threads people being able to put their hand into the intake tube of the air box and just push the filter out. With the addition of the hexagonal mesh it's not possible to do it that way any more. I haven't taken the Highlander out yet, but I'll let everyone know if I notice any difference tomorrow.

 

Ok here's my how-to on removing the charcoal filter...

PLEASE DO THIS WITH CAUTION. BE AWARE THIS MAY VOID YOUR WARRANTY. DO THIS AT YOUR OWN RISK, I TAKE NO RESPONSIBILITY FOR YOUR ACTIONS. I'm merely documenting what I did.

Tools for the job: 10mm socket with a 6 inch extension and a Phillips screwdriver, Large flat tip screwdriver, 3 inch putty knife.

Step 1. - Removed the air box lid. Disconnected the 3 vacuum hoses, loosened the intake clamp, remove the MAF wire harness and loosened the two bolts holding the lid on. Tools used: 10mm socket with a 6 inch extension and a Phillips screwdriver.

Step 2. - The inside of the air box lid. That grayish object is the charcoal filter that is supposed to collect any left over gas vapor once the engine is turned off.

Step 3. - Inserted a large flat tipped screw driver in between the filter and air box housing. Once it was in I used a little force and the rivet snapped free. I did the same with the one on the opposite end. Tools used: Large flat tipped screwdriver

Step 4. - Used a putty knife to work the filter off. The rivets on the corners came off very easily. Tools used: 3inch putty knife

Step 5. - Marveled at the fruit of my labor and examined the screen on the intake. It's pretty cool looking.

Step 6. - Reinstalled the air box cover. 10mm socket with a 6 inch extension and a Phillips screwdriver.

The way I did this was as follows:
I inserted the large intake hose into the air box and slowly worked the left hinges back into place. I knew when it's in because the the lid's right side easily come to rest on the air box assembly. If it doesn't then the cover isn't on correctly. Once it seated properly, I reconnected the three vacuum hoses, snugged up the intake pipe (don't tighten the clamp just yet) , reconnected the MAF sensor harness, tightened the two bolts securing the cover, then tightened the intake air hose clamp until its on there pretty tight.

 

Thanks for the step-by-step photo shoot! ics:

I'm most interested in any mileage gains with the filter removed. When you have any concrete results by all means post them. I'd do the process myself and test the mileage thing, but removing and reinstalling my main air filter housing is such a bitch it's something I don't like to do unless I absolutely have to.

 

Thanks for the step-by-step photo shoot! ics:

I'm most interested in any mileage gains with the filter removed. When you have any concrete results by all means post them. I'd do the process myself and test the mileage thing, but removing and reinstalling my main air filter housing is such a bitch it's something I don't like to do unless I absolutely have to.

It's gonna be a while before I can get a good milage check on the car as I'm going on vacation in a few days and until then I'm restricted to Chicago city driving. :headbang:

I'll know when I get back and take my usual 360 mile trip to see the in-laws. I always average 21 mph (It's like the autobahn going through Michigan.)

On another note, I didn't think of resetting my ECU. I'm gonna unplug the battery in the morning and reset it. I swapped out the air filter for a K&N just two days ago so it's worth the reset. I'll keep you updated!

 

Thanks. I read through the Tacoma thread like Allen had suggested and decided to go for it and remove the filter. Makes total sense to me that it's only exists for "emission" reasons and has nothing to do with filtering air into the engine, except restricting that flow. I'm removing it this afternoon and will report back to the group by bumping this thread and letting you know any mileage or performance changes.

:thumbsup:

 

Thanks. I read through the Tacoma thread like Allen had suggested and decided to go for it and remove the filter. Makes total sense to me that it's only exists for "emission" reasons and has nothing to do with filtering air into the engine, except restricting that flow. I'm removing it this afternoon and will report back to the group by bumping this thread and letting you know any mileage or performance changes.

:thumbsup:

Looking forward to hearing the results you find TD...Keep us posted..

 

I'm guessing the honeycomb has something to do with smoothing turbulent airflow past the sensor?

 

Lawfarm, you're right. The design of that mesh is very deliberate and it would have been cheaper to have used a simple wire mesh if its purpose was to only keep people from messing with the charcoal element.

 

wonder if u will get a check eng light after u disconnect battery for any reason. wouldnt the ecu register changed flow and adjust accordingly withoutbatt ecu reset?

grez

 

wonder if u will get a check eng light after u disconnect battery for any reason. wouldnt the ecu register changed flow and adjust accordingly withoutbatt ecu reset?

grez

Good question, fortunately I did not get any engine warnings. I disconnected the battery for about 1/2 hour before reconnecting it. Why? Based on what I've read on other forums the learning curve takes a lot longer if you don't reset the ECU values. By zeroing out the values the adjustment happens much faster.

Whether this is true or not, I'm not an expert, but many others are adament about the ECU reset after engine mods.

TrailDust, I lucked out, I have to go up to GR and back (180 miles each way) on Wednesday so I'll be able to get a good read. I've done this trip quite a bit so I know what I average on those trips. I've tracked my milage from day one of purchase, I'll definately know if something is different. I look forward to your observations.

 

Can't wait to see some results... this thread is starting to feel a little "sticky"!

DeWat

 

Ummmm, if someone is bored and wants to know more about the hexagonal mess this article was pretty interesting....


http://www.quest-global.com/downloads/SAE_ARAI_Paper_From_QuEST_June06_2006.pdf

 

Like I told Becks in another thread, I removed the charcoal filter today. However, there's wasn't enough time for the K&N filter to dry before I re-oiled it so I put the OEM filter back in. I'll run a few tanks with that, then run a few with the K&N back in. I'm not expecting much difference, but I'll take every fraction I can get.

 

Thanks for the update TD, I'm itching to start my long round trip on Wednesday. That will be my definitive test for my increase or decrease in MPG as I'm a pretty hard highway driver but with a regular pattern. I usually get 21.4 MPG on average for my last 11 trips to Grand Rapids. I'm usually driving 80mph (128kph) to 85mph (136 kph) for the majority of the trip from Chicago. Any improvement for me would be a blessing. I wish I could get the milage you mentioned in the other thread just now! I'm slowly learning to lighten up on my lead foot.

I will note, disconnecting my battery and resetting the ECU did make my car run a bit smoother.

 

Well, I got a really good run with the HL today.

First the good news, the pickup and acceleration on HL is definately better. The HL was rock solid at 80 MPH to 85 MPH and the acceleration from a stand still to 80 was incredible.

The bad news....I didn't notice an increase in my gas milage. I seemed to have averaged the same 21 MPG that I normally do. Keep in mind I have a heavy foot, have the A/C blasting and the radio cranked way up. I will say when I was forced to drive much slower it did look like the car was registering a much better MPG then I've ever seen at a steady 60 to 65 MPH. Also, I wonder if the MPG will increase as the system continues to adjust for the change.

Perhaps those with more sensible driving habits might see a much better fuel economy that I've seen.

TrailDust, have you had a chance to test yet? Just curious.

 

TrailDust, have you had a chance to test yet? Just curious.

Not yet, but starting tomorrow I'll be pretty much chugging down a tankful of gas most ricky tick in driving that'll be 50/50 city and highway. With luck I'll be able to do a purely highway run in the next two or three weeks, then put the K&N back in and check the numbers with that. I love testing stuff....

 

Thank for the update VorlonBlue, I think that I'll remove my charcoal filter tonight.

 

Hey Edwindiaz5, any luck with the filter removal? Did it go smoothly, did you test it out yet?

 

Hey Edwindiaz5, any luck with the filter removal? Did it go smoothly, did you test it out yet?

Yes, I did remove the filter and I love the change. The engine sounds more aggressive and the throttle response is better. I do have a K&N filter in my HL wish it helps. I kept the charcoal filter just in case I needed it for the smog inspection since I live in Cali and the laws here are more rigid.

 

Any news from anyone on this? So far I've had a sustained increase in acceleration since the removal. No difference in fuel consumption.

 

Inconclusive since I haven't driven much lately and only put one full tank through since removing the filter. Probably be a couple months for me to chime in after two or three runs to the desert, etc., with the paper filter in and then swapping out for the K&N. My first tank was 60/40 (city/highway), and produced 21.8 MPG. Given the amount of A/C used, hauling a couple of heavy loads and such, it's in the ballpark of similar tanks.

 

As with most improvements that increase airflow (better filter, larger/smoother intake, etc.), it makes sense that the gains you experience are concentrated at WOT. When not operating at WOT, the biggest restriction in the intake is the throttle butterfly being controlled by your right foot. I wouldn't expect overall efficiency gains, but slightly better WOT performance and more noise seem like a reasonable outcome.

 

It's alive! I had to resurrect this thread. I've had the charcoal filter off now for about 5 months and my observation is that my acceleration and pick up have increased, no change to MPG but that wasn't what I was shooting for. The filter is very restrictive, not sure this was part of the engineers original vision for this engine, it's placement seems like a "oh crap we have to do something to comply with a new CA regulation so let's just slap this filter in there" type of a thing.

Has anyone else tried this and any observations?

 

I did this in my Sequoia and my mileage went from 14 mpg to 29 mpg :facepalm:

 

Any other tweaks or mods for this change. I'm going to remove my air box charcoal filter on my 08 Sequoia. Does the engine control module compensate for the difference in airflow?

Thanks.

 

Disconnecting the battery shouldn't be necessary. The adjustment of the air-fuel ratio is done continuously by the two O2 sensors in the exhaust. This is necessary to pass emissions due to changes in outside temperature, humidity, altitude, and engine temp.

 

Charchol filter Removal

Did mine yesterday. Other posters are right. The filter itself was very restrictive, couldn't blow much air though it and only have 16000 kms on my unit!

Went for a drive out on the highway and noticed a nice improvement. HL pulls like a little bear up to about 80 mph! Rev's much cleaner! Even shifts better!

The engine seems much smoother as well. Also noticed that the instantaneous mileage read out is much more stable and was down under its usual 11 litres/100 reading while cruising at 100 kph, who knows if its right or will have a substantial effect on overall gas mileage.

Regardless, off to Florida in a week so will know if there is a mileage improvement.

I do know that the HL runs better without it! Therefore, its not going back in!

 

Did mine yesterday. Other posters are right. The filter itself was very restrictive, couldn't blow much air though it and only have 16000 kms on my unit!

Went for a drive out on the highway and noticed a nice improvement. HL pulls like a little bear up to about 80 mph! Rev's much cleaner! Even shifts better!

The engine seems much smoother as well. Also noticed that the instantaneous mileage read out is much more stable and was down under its usual 11 litres/100 reading while cruising at 100 kph, who knows if its right or will have a substantial effect on overall gas mileage.

Regardless, off to Florida in a week so will know if there is a mileage improvement.

I do know that the HL runs better without it! Therefore, its not going back in!

When you say that "the instantaneous mileage read out is much more stable and was down under its usual 11 litres/100 reading while cruising at 100 kph", do you mean that your mileage appeared to be worse?

Thanks,
DeWat

 

mtc46jw, awesome. I haven't looked back since I removed mine.

I would be curious to see if you have an improvement in mpg. I didn't, but I'm the worst driver in terms of mpg so I wasn't looking for an improvement.

I drove a hybrid rental recently and I swear the thing would shudder whenever I walked up to it. :facepalm:

 

To any Klugger owners, do you have the same charcoal filters in the top of your airboxes? I'm curious if these are only present in the N/A based models.

I'm only asking because I saw on some other forums that BMW owners have done the same mod and they mentioned the European versions didn't have the filters in place.

 

I did pose the question in an Australia Kluger forum (http://au.toyotaownersclub.com/forums/index.php?showtopic=25204) but the only response I've had was inconclusive.

I don't really want to go to all the trouble of opening up the airbox to find out there isn't one. I've been intending to install a K&N filter, and would check the charcoal filter at the sma e time, but haven't gotten around to getting one yet (also I haven't really seen anything which conclusively shows there are any worthwhile gains with the K&N filter).

 

charcoal filter removal

I also have a thread about this. Highlander, Kluger poor mileage - SOLVED
I removed charcoal filter last week.

Since then I took a trip from Northwest CT to Long Island a 260 mile round trip. Elevation difference of 630 feet with a total 4 people (3 + driver).

My mpg for the entire trip was 23 mpg. It would have been 25 mpg... but the last part of the trip is mostly up hill! Amazing! Also performance and braking improved.

Before it took out the permanent filter I was getting 14 mpg! Bingo!

Now you tell me?

Why is this not a replaceable filter. Why is it not mentioned in Haynes or anywhere else?
I think you guys are right... this is a money maker for service dealers.

How many millions of owners are facing this problem and don't have a clue?

 

Thanks CT!

Thanks for reviving this thread CT_Highlander. I hate to :deadhorse but this is really a quick fix.

I've done this same filter "enhancement" on a number of other Highlanders for friends and my sister. They've all gotten either an increase in performance or better mileage. (Depending on how they drive). I'm a lead foot and there's no saving me. My sister is a MPG oriented driver and she noticed a huge change right away.

It's amazing how restrictive that filter really is, even when it's not too dirty. The filter was an afterthought that was placed there to capture any stray gas emissions when the engine is turned off. I think the improvement in mileage offsets the about of stray gas the filter absorbs.

It's really a simple fix that shouldn't take more than 20 minutes to perform.