PCV.. Breather.. What is it?

I'm getting ready to put together my cold air intake. I have a cone filter in a closed box mounted directly on the MAF, and a hose running down as a cold air draw. Here's the question: The hose that runs from the valve cover to the airbox, and has a little sponge thing where it comes out.. What is it? I've tried looking but I don't even know what to search for because I don't have words to explain it.

When I install my new intake, where should I run this hose to? Can I replace it with a breather filter, or just hook up the other end to somewhere on my cold air draw hose?

Any advice would be appreciated. I don't like to start new threads about things that have surely been discussed before, but I don't even have a clue on what to search for.

All it is a breather port for the oil. Look at the SleeperZ intake sticky and you will see the breather next to his air box. You can find the breathers for cheap at an autopart store if you want to upgrade.

The PCV valve allows crankcase gases to be vented so as not to cause undue damage to the engine. The breather filters out the oil from the gases before reintroducing said gases into the stock eir intake. In anything but a stock intake, it simply filters out the oil before venting it into the engine compartment.

OK, so if the hose doesn't go back to the intake, it doesn't matter? That's what I figured, seeing as it went into the airbox rather than downstream of the MAF. Barring any hood clearance issues, I'll probably just remove the hose and put a breather filter right on the hole in the valve cover.

Originally posted by mcgarvey:
OK, so if the hose doesn't go back to the intake, it doesn't matter? That's what I figured, seeing as it went into the airbox rather than downstream of the MAF. Barring any hood clearance issues, I'll probably just remove the hose and put a breather filter right on the hole in the valve cover.

If it fits, I tried that and the squeeze was a bit much (fuel rail was in the way I think), so I used the stock hose and connected it to a breather and laid that next to the air box.