wlbrtsmth3

Hey guys..I have a 2000 TL and I want to replace the fuel pressure regulator. My issue is that I keep seeing guys swap out the fpr on the back rail and they never show a second one. However when I go to purchase one from autozone, oreilly's, etc. They have the option for an fpr "to engine" and "from engine" one has greater psi than the other. Can someone tell me which one to replace? I have the heat soak condition also described as vapor lock

01acls

Behind the throttle body... black dot.