Just had my oil change at speedy for my 2002 xterra 3.0. The bums spilled oil on the power steering reservoir and the side of the engine. I won't go their again. The truck has 62k and can't locate the pcv valve which should be replaced. BTW my oil is slightly dirty after an oil change could this be caused by a bad pcv valve.

The oil will get dark fairly quickly, it's not a sign of a problem.
As for the PCV valve, it's on the upper driver's side of the intake plenum towards the rear, pretty much in-line with the last N in NISSAN if you're standing by the driver's fender.