Replacing the PCV?

Do you have a pre-2001 V6 with the PVC pulling in oil? If so, that is caused by the design of the valve cover and the lack of a baffle. Best way to fix the oil coming into the intake of a pre-2001 is to stick an inline filter with some 3/8ths inch hose and clamps to catch the oil. http://www.miracerros.com/mustang/pcv_filter.htm there's some good information on that subject.

Well, the reason gas milage is lower on it is because the PVC pulls in oil from the crankcase and into the intake. It's a design flaw in the valve covers that has been known for years, older cars just came with oil separators. Some have claimed a good 1.5mpg increase just by adding that filter in the PVC tube. It could be the valve itself, but I do know the 99-00 pulled in so much oil. Cost me about $10 for an inline fuel filter, 3/8" hose, and 4 clamps. Takes alittle work, but it does increase gas milage, reduces risk of detonation, reduces emmisions and improves the overall life of the engine by not burning oil.

I have seen the pic at link posted above ,with the filter installed.Could you ellaborate alittle on the installation process.It looks as if you need to cut the stock tube from the intake to the PCV valve...is this correct? Does this set off any emission codes or etc.?...please explain

Yes, you cut the PVC hose to fit the filter in, then use a 3/8" hose to go around the PVC hose and filter fittings, and clamps to hold them tight. It should not set off any emmission codes or fail because it still permits the crankcase gases to reach into the intake like it was designed for, the filter only prevents the oil from reaching inside the intake which is not intended.