What size speakers are in your Mazda 2001 mpv?
"Where is the PCV valve on a 2001 Mazda MPV?" I have done this and it's very hard to see. It's on the back side of the motor, somewhere behind the throttle body. Got to WWW.MPVCLUB.COM and ask there. I put pictures in a thread about it but it was long ago and I don't know if the pics are still around or how hard it will be to find the thread.