what is a pcv valve, and where is it located?

 

PCV is the Positive Crankcase Ventilation valve. It takes fumes from the crankcase and puts them into the intake so they can be burned. On your truck, it's on the passenger side of the engine, partially hidden by the Hemi Hat. Once you've removed the hat (easy to do), it will look like a miniature gas cap near the throttle body. I had to use pliers to twist it loose. If yours is the original, it needs to be cleaned at least, maybe replaced. Cleaning is easy, using brake cleaner. If the ball inside it doesn't move easily after cleaning, you'll need to replace it. Hard to find here (had to go to the dealer), but in many places, NAPA has it in stock. A bit pricey ($27 or so) compared to the $5 ones.