I need your thoughts on replacing the PCV on my '07 Focus. Car has 136,xxx miles on the clock and as the second owner I've had the car for about a year. As far as I've been able to tell the previous owner used Mobil 1 and that's what I also use with 6-7000 mile OCIs. So, the question is do you think I should change the PCV? The engine does not use any oil and runs very well. I ask about replacing the PCV because if I don't have to it will save me a lot of work as the PCV is a PITA to get to.