'I have been through this on my 94 Altima, and let me warn you, it's not a walk in the park by any stretch of the imagination. The PCV valve is located beneath the intake manifold on the right (passenger) side. It threads into the breather seperator and points toward the center of the car. To remove it, you'll have to remove the Idle Air Control valve located on the end of the manifold log. Be aware that you'll have to do at least part of this task underneath the car, and that the IAC valve has antifreeze circulating through it (I found this out the HARD way!!!!!). It also might help to unbolt the breather seperator from the head. If you can afford it, pay a mechanic if it really needs to be done.