merace19

I changed the air filter yesterday on my wifes 06 4.0 and it looks like another filter was inline with the air filter. It is on the motor side of the intake. i tried to pop it out to look at it, but it would not come out. I did not mess with it after that. Does that have to be in there? It looks like a BIG restriction and if removed could free up some gas mileage.

BlakeTTS

I noticed the same thing when I put the K&N in. First tried to remove that one, without noticing the actual filter on the other side. Looked to me like that needed to be in there. However, if it can come out with a new filter in there, let me know what kind of mileage you get as I have the same engine.

merace19

Looks like a charcoal filter to me. I would love to know what it is. But I am not due to go back to the Toyota dealer any time soon so if anybody knows what it is let us know.
thanks

Jacket

It's a secondary air filter - helps to reduce emissions. Some guys have opted to remove it, believing there's HP to gain with it out of the way. There's a very detailed discussion of it here:

http://www.toyotanation.com/forum/t89620.html

merace19

Thanks

merace19

I pulled mine out. Seen no reason to keep it. Did notice that after that and K&n filter put in my MPG went from 19 to 22.1

BlakeTTS

So I went through all 15 pages of that forum that is above, and here is what I came up with...
If you were ever considering putting a cold air intake/ram intake on the vehicle, it would be the same thing as pulling that charcoal filter out.
So what did I do yesterday? Pulled that sucker out. I do have to say that it did feel a little peppier than before, maybe Im trippin, but something extra was there, just a tad. Very easy to pop off, take that with the K&N and Im showing 22.3 mpg. However that has not been reflected on a full tank of gas, however with the digital readout (if you go by that) has that rating after 25 miles.

merace19

I used a razor blade to cut the tips off the pins. Drilling them out too deep and you could hit the box. Took 10 minutes total.

AH64ID

From what I have read on TTORA there is no reason to remove it, as with it removed there were no real gains... .It probally also messes with your warrenty removing it, espically since you had to drill and cut it out, not easy to put back in

And those of you with K&N, if you like your engine you should take it out, they are close to the worst thing you can do to a motor.

BlakeTTS

You have to admit that the thing is restrictive. Plus if you are planning on selling the thing in a few years then who cares right?

merace19

Yeah K&n are bad. I aint keeping this thing forever. I put 275k miles on a chevy and only changed the oil 5 times at the most. It ran out of oil all the time so i would just refill it. It would only start burning it after about 25k miles. then it would go though it pretty fast. Air filter I poked holes in the filter to let air get past it. It got changed maybe 3 times.

As ffar as the toyota 4runner I am only looking to increase the mileage I got the air filter for free. so its better than nothing.

AH64ID

Hmm, not a philosophy I take....

tderose

What makes you say that? While it's true the K and N allows more dust and dirt into the intake, it also allows more air flow as well, and is less restrictive than the OE filter. However, the OE filter traps more dirt allowing less behind it into the intake. Why not use both? The K and N for on-road driving where lots of dirt is not an issue, and an OE filter for off-road use when you need to trap more dust, dirt, and other particles. Just a thought?

merace19

I have raced on a dirt track for 10 years and on pavement for 2. I rebuilt the engine every winter and when I tore them yes them as in many other peoples engines as well I never found any damaged caused by dirt. But these engines only had a few 100 miles on them but at 7-9k rpm.
When someone can show me a engine that was driven 99% of the time on paved roads and it has engine damage due to dirt or dust from a K&N filter that was washed like it should and oiled like it should then I will stop using them. But to spout off that they are bad Just because Joe blow said so Dont hold water with me.

AH64ID

The dirt will prematurely cause your rings to wear, and dirties your oil quicker. What the oil filter doesn't catch will circulate thru your engine. Also the oil on K&N's has been known to gum up MAF's... both things I would consider pretty darn hard and bad for an engine.

There are other filters that stop more dirt and flow as much air, so why buy a K&N?? Trueflow is an example of a much better filter, better on and off road.. .Not too much $$$, similar to K&N, and you dont have to swap filters.

K&N's are decent for hwy rigs, but you still have the oil on the MAF issue.....

tderose

I can agree with that only if you have someone who overoils the filter. Overoiling the K & N's will cause that problem as you stated. I've had mine for 2 years now with no MAF issues, and no dirt behind the filter in the intake. I will most likely switch to TrueFlow or OE at some point in the future, but the K and N is fine for now as I've done about 90% on road driving this past year. I still believe they are good filters as long as you don't overoil them.

AH64ID

Problem is they come overoiled in the box many times, and most people dont know better and treat that as normal.

merace19

The excess oil gets sucked out almost as soon as you start the engine. I had a filter that got clogged with mud the was being thrown up during tract packing. I had to clean it real quick and just poored the oil to it. I cranked it to see what would happen. It sucked it right up. I am sure that on the newer cars and trucks it could get on some sensors but with that much air being moved past it. The oil gets sucked into engine and burned.

AH64ID

It puts oil into the air more than just at startup, and like when it snows your going to get a fine mist over everything, including sensors.

merace19

I just dont see it causing problems. You only have to oil it every change and most times I go about 25-30k between cleanings. So easy to squirt cleaner on the sensors after about 100 miles or so to clean the excess off if you are worried about the oil on them..