K&N Air Filter

[jonny-rockets]

I got one of the panel filters, its being shipped. This will not provide such a higher flow of air that I would be running lean right?

Anyone else throw a K&N panel filter in? Ever have a CEL from it?

http://websmileys.com/sm/violent/sterb008.gif

[GrassyKnoll]

ive never gotten CEL and i ran one for a year and a half before i got rid of the old car

[jonny-rockets]

cool. http://websmileys.com/sm/cool/1237.gif

[Murphy2012]

Youre fine

[04silvrrex]

I run a panel filter.. your good.... I don't think it takes in so much air that it will lean it out, also so ecu is smart enuff to adjust to something like that( a little increase in airflow)

[HamSocks]

I've read Subarus run pretty rich anyways, is this correct?

[kgj996]

The only way you would get a cel is if you changed the MAF tube diameter, or caused a lot of turbulence before the maf and through off the readings. The only mod that will cause this is a short ram/cold air intake with a different size maf tube or a poor design. The cobb short ram has air straighteners before the maf to keep the readings correct and they use the stock diameter. I used to have a homemade airbox lid that held the panel filter in but deleated the rest of the stock intake. It worked well and made that sweet shortram intake sound.

[04silvrrex]

ya the intake silencer delete... first mod i did..:)

[jonny-rockets]

ya i def read somewhere before that wrx's run rich from the factory... hmmm..

intake silencer + k&n on the list for next mods.

[ValuePack]

I've owned four K&N drop in filters with no issues other than poor fitment on a Ford application. You're fine.


I've read Subarus run pretty rich anyways, is this correct?

Yep, that's about the size of it.




Amsoil is better.
*runs like *****

[Nick S.]

Increasing airflow is always good as long as the MAF has accurate data like Kevin stated.

The ECU controls A/F ratios 2 ways.

1.) In closed loop (after the car has warmed up), in non wide open throttle (WOT) conditions the ECU takes inputs from the MAF sensor, compares it to the longterm fuel trim maps and calculates injector pulse width then looks at the narrow band O2 sensor reading to see how close it was and adjusts the next pulse based on that until it gets the O2 sensor cycling back and forth around 14.7:1.

2.) WOT or open loop (while the car is warming up) The ECU calculates based on airflow then figures out what the injector pulse width should be to get the proper A/F ratio in its WOT fuel map. Then it doesn't check it against anything. (No use of the narrow band O2 here just guessing).

The stock WOT fuel maps are set to run rich because the richer the mixture the less knock you can potentially get (plus the ECU isn't comparing its calculation to the O2 sensor anymore because it will be way richer under WOT, around 9:1 to 10:1.) However the richer the mixture you start loseing power.

Which is why tuning with a wideband kicks ass. You can dial in the exact WOT fuel map you want the ECU to use to get more power without knocking.

[Skidder]

I herd about some issues with K&N, such as:

1) the filter oil gunking up the map sensor
2) it not filtering very well

Is there a brand of air filter out there that has superior filtering (sort of like how OEM Subaru oil filters claim to be)

[jonny-rockets]

i suppose 1 could happen to people who over oil their filters. you only need a little oil.

i have used k&n filters in 2 cars and 1 bike now and never had a problem. this will be the 3rd car to put it in.

[jonny-rockets]

wow literally took 20 seconds to install. best mod evar.