I'm trying to find out exactly where the PCV is located on a 99 Navigator. It is a 5.4L v8. I have two codes reading 171 and 174 too lean bank 1 and 2. I've read a repair manual but my engine looks nothing like the one in the book. The elbow had a hole in it and the replacement doesn't fit right but thats a whole different story. I read where I should check the vacuum on the PCV valve by removing it and can't find it to do that. Thanks for the help. My son has tried to help me but no luck there either.