Ok, say I remove the accordian tube...and get to the pcv valve, replacing is pretty easy, right? And Cheap?

As far as clogging...I never did anything to the pre-cats. Just let them burn off and blow all that **** out by itself. Seems to run okay. Only problem is the oil consumption is up.

Mine is a '95. Say I have bad O2 sensors, will this just cause the car to run rich? My mileage may be down some too--not a lot. Will the timing retard? And how much to replace an O2 sensor?