How to Replace the Engine Air Filter
by G6CivCX

Parts Required:

• replacement air filter

Required tools:

• gloves

Required time:

• 5 minutes

Background

The air filter’s job is to clean impurities from the air that is going into the engine. The factory recommended replacement interval is every 2-year, 30,000 miles, whichever comes first. If you live in a dusty area, you should replace it once every 1-year, 15,000 miles.

I recommend the K&N OEM replacement drop-in. It’s a permanent air filter that comes pre-oiled. It will also help you make a few horsepowers.

Here is a side-by-side comparison with the stock filter and a K&N filter. It's a good idea to wear gloves because the filter is very oily.


Clean the filter at the replacement intervals for the stock filter. Consult K&N for cleaning instructions.

1. Park the vehicle in a safe place. Stop the engine. Open the hood and support it using the prop rod.

2. The airbox is located near the battery, on the driver’s side.

3. Here’s looking straight down at it. Notice that there are four (4) spring clips holding the top of the airbox.

4. Pop the spring clips off with your finger. It should come out very easily.

5. Move the top of the airbox up and slide it out of the snorkel. It should come out very easily.

6. Clean the immediate surrounding area. Make sure that debris will not fall into the intake tract after you remove the air filter.
7. Take a careful look of the air filter. Notice how it’s sitting. You want the new filter to sit there just like it is. Notice that the bottom has a raised edge to make a nice, air-tight seal.

8. Just pull the old filter up and out. Be careful and don’t drop anything down the intake tract.

9. The filter looks square, but it’s really rectangular. As such, it will only fit correctly in one orientation. Note that this is the incorrect orientation.

10. This is the correct orientation.

11. Replace the cover by first inserting it into the snorkel to make an air-tight seal, then placing it over the air filter.
12. Put a little pressure down on the cover to seal it. Tighten the 4 spring clips. They may take a little pressure to get back on. So take your time and be patient. Once you get one on, the rest should be easy.
13. Turn on the engine and check for leak.

 

I did this same mod with the K&N filter. What struck me was the appearance that the K&N seems to have less filter material area than the stock filter. Look at the top pic and it would seem the K&N has about 80% of the stock's surface area available. The K&N has the rubber from the filter frame bleeding onto the edges of the filter material all around the sides, which takes some square inches away from the equation. I know K&N claims the filter is more efficient than stock, but to look at it you'd think the opposite.

Power seems to be about the same, but people have said they think the intake noise is greater now with the K&N added. I didn't notice a change.

 

It has less surface area, but is supposedly able to filter out smaller particles as compared to stock. That's the engineering behind it.

And it has been shown to make 2-4 bhp on the dyno as compared to the stock filter.

I like it because I don't have to buy another air filter, ever.

 

The performance angle on the K&N is supposedly the filter material is more efficient and allows for more air volume to flow thru it than the stock material.

I like the "clean it rather than replace it" aspect, too. Just recharge it once a year and you're golden.

 

I got mine for $70 shipped. An OEM Mitsubishi filter costs me about $20 from the dealer. I refuse to use Fram.

This filter will last me more than 3 filter changes. And since I drive my car a lot, that's sooner than later.

 

wow, a how-to that even an idiot like myself can follow! thanx

 

Thanks for the praise. I always try to err on the side of too much details. I understand it's hard to follow something that has a few pictures and words, and sometimes not even that.

 

Did anyone notice the turbo spooling up quicker?

 

Great write up! Might want to include the part # of the K&N filter.

 

this is a joke right? a write up on changing a stock Air Filter??

wait....next i'll do a "how-to" on pumping gas....

 

Can you next please do a writeup on how to add more washer fluid? Thanks

 

I can't tell the difference. It's really hard to tell without a dyno. I don't imagine it would be that much quicker.

Thank you. K&N air filter part # 33-2105. See link for more details.
http://www.knfilterchargers.com/sear...x?Prod=33-2105

No, this isn't a joke. If you're too smart for this kind of write-up, don't read it. I wrote it up because someone has requested it.

Actually, I may just write up an article on how to add fluid to the intercooler spray reservoir. We get way too many questions about overfilling.


Thanks for the praise. I'm looking to do a lot more comprehensive write-ups in the future, including clutch replacement and cam swaps, etc. This little article was just to test some things out.

Cheers

 

Did anyone`s warrenty get voided for just the K&N panel filter?

 

If you don't know how to do simple things like this, you don't deserve to drive this car. Sorry, it's not a civic.

Very nice pictures though. I wish all DYI have pictures like that.

 

true tat!