Switching back to the factory air filter

[cormorant tail kite]

Hi all.
I'm wondering if any of you know if it's a big job to go back to the factory air filter set up? What briefly needs to be done? Cost a lot? I'm somewhat capable of tinkering on some things, I did my screaming monkies, ha.
Im the third owner of my LJ and one of the other owners put one of the K and N filter setups on her. I have read some not so great for jeeps, sounds too different from my previous jeeps, and would like to go back to factory. Any insight would be great.
Thank you

 

[nk24]

You would be wise to go back to the stock air cleaner box. It won't take much time or effort once you obtain a stock box. Just make sure you get the correct box and tube for your model year. Looks like you have a 2005, so you will need to get the 05-06 box with the sensor on the back of the tube. You'll also need to get one of these if the K&N setup doesn't fit: https://www.ebay.com/itm/3019953936...d=link&campid=5337789113&toolid=20001&mkevt=1

You'll probably need to remove a few clamps on the K&N setup, plus a couple bolts that hold it to the right side fender. Stock box will be replaced in a similar manner, with a few bolts on the fender and a clamp on either side of the tube.

 

[Dunkut88TJ]

X2 to what he said, very easy 20 minute job, did mine a while back. Hardest part will be finding a decent stock airbox

 

[nk24]

X2 to what he said, very easy 20 minute job, did mine a while back. Hardest part will be finding a decent stock airbox

Yep, I paid about $130 at a junk yard for mine earlier this year. If you pay top dollar, make sure it is complete with all the hardware, clamps, and clips.

 

[Dunkut88TJ]

Yep, I paid about $130 at a junk yard for mine earlier this year. If you pay top dollar, make sure it is complete with all the hardware, clamps, and clips.

I paid 80$ and it had the set up for both 4.0’s. Mine had some holes on the bottom, but I gorilla taped it shut and moved on. Still better than the cold air intake.

 

[Mac]

I have a K&N filter system - what are the draw backs? My Jeep is a Daily Driver and I am really concern about what issues the K&N filters cause. Your concerns would be helpful for me to decide if — I too should change to a STOCK OEM filter system. Thanks.

 

[Gollywomper]

I have a K&N filter system - what are the draw backs? My Jeep is a Daily Driver and I am really concern about what issues the K&N filters cause. Your concerns would be helpful for me to decide if — I too should change to a STOCK OEM filter system. Thanks.

They don’t work very well. Every thing I have ever had a K&N on had dirt in the carb. I still run the fake air intake. However I use a paper filter and an “outerwear” sock over it. I think the paper filter is from a mid-early 90s Honda prelude? Could be wrong though. I could not go back to a stock box due to hiline fenders.

 

[Jerry Bransford]

I have a K&N filter system - what are the draw backs? My Jeep is a Daily Driver and I am really concern about what issues the K&N filters cause. Your concerns would be helpful for me to decide if — I too should change to a STOCK OEM filter system. Thanks.

A K&N is absolutely the worst for actually filtering harmful particulates from the air passing through the engine. Before I learned that I had to place TWO prefilters over the K&N I used to run to reduce how much dirt and dust was getting into my engine. An absurd amount.

Look at the comments at the bottom of the attached chart of results from an ISO conducted lab test of various air filters.

 

[LONGJP2]

Mostly there's no benefit to having one. They really only add power at really high RPMs. Even then, the Jeep 4.0 already uses as much air as it already gets with the stock intake.

 

[Dunkut88TJ]

A K&N is absolutely the worst for actually filtering harmful particulates from the air passing through the engine. Before I learned that I had to place TWO prefilters over the K&N I used to run to reduce how much dirt and dust was getting into my engine. An absurd amount.

Look at the comments at the bottom of the attached chart of results from an ISO conducted lab test of various air filters.

View attachment 255114

I was just about to tag you for this chart!

 

[Mac]

A K&N is absolutely the worst for actually filtering harmful particulates from the air passing through the engine. Before I learned that I had to place TWO prefilters over the K&N I used to run to reduce how much dirt and dust was getting into my engine. An absurd amount.

Look at the comments at the bottom of the attached chart of results from an ISO conducted lab test of various air filters.

View attachment 255114

Thanks - NOW I KNOW.. and until now I was DUM and HAPPY... and now I can be smart and SAD! As I need to spend more money to get the old boy back to STOCK!! But thanks again, I never heard of these problems before, again many thanks.

 

[rjinaz86323]

I paid 80$ and it had the set up for both 4.0’s. Mine had some holes on the bottom, but I gorilla taped it shut and moved on. Still better than the cold air intake.

WOW. You guys must go to 'boutique junk yards'. I bought one a couple of months ago for $30

 

[Sudo]

I'm looking for a tube for 05-06. I have a tube for earlier models if someone need it.

 

[cormorant tail kite]

You would be wise to go back to the stock air cleaner box. It won't take much time or effort once you obtain a stock box. Just make sure you get the correct box and tube for your model year. Looks like you have a 2005, so you will need to get the 05-06 box with the sensor on the back of the tube. You'll also need to get one of these if the K&N setup doesn't fit: https://www.ebay.com/itm/3019953936...d=link&campid=5337789113&toolid=20001&mkevt=1

You'll probably need to remove a few clamps on the K&N setup, plus a couple bolts that hold it to the right side fender. Stock box will be replaced in a similar manner, with a few bolts on the fender and a clamp on either side of the tube.

Thank you for your detailed response, and thank you for posting the link to purchase the hose. I have posted a photo of my setup, is the hose from your link the smaller hose right behind the large k&n?
Yes, I have a 2005 unlimited.
I found a drawing of the air cleaner assembly, I know they are out of stock on there, just using it as a guide. Are these all of the parts I need to make sure comes with my purchase?
And this small hose may work?
It all is a bit confusing, just hard to grasp when things are not the same and more little components are needed. And of course when I might have to end up buying the parts from different places.
Why couldn't I have a 2004, ha, these assembly's seem to be all over for sale.
I found a box for my year, that's about it. Looks like this k&n hose duct is too large to go into new box, unfortunately.
I'll call around some junk yards tomorrow, not too many around have jeeps, will widen my reach

 

[cormorant tail kite]

A K&N is absolutely the worst for actually filtering harmful particulates from the air passing through the engine. Before I learned that I had to place TWO prefilters over the K&N I used to run to reduce how much dirt and dust was getting into my engine. An absurd amount.

Look at the comments at the bottom of the attached chart of results from an ISO conducted lab test of various air filters.

View attachment 255114

Curious what prefilter you used to put over your k&n? Im thinking about maybe doing that until I find all of my stock parts I need.
Also, once I take this k&n off, is it pretty easy to see if there is any dirt in the openings on jeep and clean it out before I put the factory assembly on?

 

[nk24]

Thank you for your detailed response, and thank you for posting the link to purchase the hose. I have posted a photo of my setup, is the hose from your link the smaller hose right behind the large k&n?
Yes, I have a 2005 unlimited.
I found a drawing of the air cleaner assembly, I know they are out of stock on there, just using it as a guide. Are these all of the parts I need to make sure comes with my purchase?
And this small hose may work?
It all is a bit confusing, just hard to grasp when things are not the same and more little components are needed. And of course when I might have to end up buying the parts from different places.
Why couldn't I have a 2004, ha, these assembly's seem to be all over for sale.
I found a box for my year, that's about it. Looks like this k&n hose duct is too large to go into new box, unfortunately.
I'll call around some junk yards tomorrow, not too many around have jeeps, will widen my reach

View attachment 255882

View attachment 255884

View attachment 255885

The hose circled below won't be long enough to reach the stock air box. The hose I linked to above will replace it.

 

[nk24]

Thank you for your detailed response, and thank you for posting the link to purchase the hose. I have posted a photo of my setup, is the hose from your link the smaller hose right behind the large k&n?
Yes, I have a 2005 unlimited.
I found a drawing of the air cleaner assembly, I know they are out of stock on there, just using it as a guide. Are these all of the parts I need to make sure comes with my purchase?
And this small hose may work?
It all is a bit confusing, just hard to grasp when things are not the same and more little components are needed. And of course when I might have to end up buying the parts from different places.
Why couldn't I have a 2004, ha, these assembly's seem to be all over for sale.
I found a box for my year, that's about it. Looks like this k&n hose duct is too large to go into new box, unfortunately.
I'll call around some junk yards tomorrow, not too many around have jeeps, will widen my reach

View attachment 255882

View attachment 255884

View attachment 255885

At a minimum you'll want to get parts 2, 4, 6, and 11. The other parts you should be able to source new.

 

[cormorant tail kite]

At a minimum you'll want to get parts 2, 4, 6, and 11. The other parts you should be able to source

Ah, thanks for pointing out the hose!
What is that little elbow, #12?
I was looking and I think I only found these for 2004 years as well

 

[Jerry Bransford]

Curious what prefilter you used to put over your k&n? Im thinking about maybe doing that until I find all of my stock parts I need.
Also, once I take this k&n off, is it pretty easy to see if there is any dirt in the openings on jeep and clean it out before I put the factory assembly on?

It took two prefilters. The first layer was K&N's Precharger which fit so loosely it allowed dust to flow in around it. That's K&N for ya! I was forced to add a foam Unifilter to hold the Outerwears closer to the base K&N so it wouldn't leak in dust.

 

[cormorant tail kite]

The hose circled below won't be long enough to reach the stock air box. The hose I linked to above will replace it.

View attachment 255897

That wire, to the right of your circle, that is going into the large k&n hose, it has one of those plastic snap connectors...will this go into the factory set up ok, doesn't need to be longer or get a new one?