do a 1997 nissan pickup,2.4liter four cyl. auto have a pcv valve i can not find one.

All automotive gasoline engines made from 1963 onward have a PCV valve, even if it goes by a different name.

try going to auto zone.com and putting in your truck and look for pvc and it may show a pic and maybe location.
Other parts stores online may also work.

No, they don’t. For example, the 3.9L V8s in my car do not have PCV valves by any name. They do, of course, have PCV systems, they just don’t have any one-way check valves. Read the factory service manual if you don’t believe me.