I need a little backup. I have a 2001 outback wagon, one of the first things that i did to it was to switch the paper element air filter to a K&N filter. About a month later the CEL came on, took it to the dealer and it was the engine idle control code, they told me that when i put the air cleaner box back together i didn't seat it correctly into the bottom tabs (not good for the ego). But then a week later the CEL came back on, the new story is that the K&N filter is drawing too much air and causing a lean condition. BS i think. Anyone had a problem with this code and could it be related to the air filter?

I'm not sure about Subarus, but on other makes I own, I have seen lots of people cause themselves nothing but grief with K&N filters. Can you get them to be specific? Is it a fuel trim problem, as they seem to be saying? What are the codes exactly? Can they share the adaptation values for fuel trim, if they say it's running rich/lean, they should be able to show you that.

 

The system should be able to adapt to the increased air flow (if there is any) with the K&N filter. However, the common problem with K&N's is that they either allow contaminents or filter oil to ruin the intake air measuring device. I know that K&N's have a huge following and people will swear that they can get 50hp with them, but on the dyno, I have yet to see a K&N get more than a couple ponies on a stock car.

All really good questions that i didn't ask. You can bet that i'll be calling first thing in the morning to get numbers on the diagnosis. Gotta tell ya there may have only been a scant few extra ponies under the hood with the K&N but since i switched back i'm really missin em. THANKS

I'd guess that K&N filters are about as effective in boosting performance as fuzzy dice. Can you reinstall the OE components, clear the computer, and see if that helps?

Put the paper element back in, now waiting to see if the CEL comes back on.

If the air filter isn't going to gain any HP then what is going to get a little more juice out of this 2.5.