Iíve had a UPR catch can on my 5.0 since last summer. It catches a lot, especially in the cold months. But Iíll get right to my test. I added an RX can inline after my UPR can to see if the UPR was missing anything. And if it was allowing some to pass through, was it enough for the RX to catch anything? I donít drive a lot of miles regularly since my F150 is not a daily driver, so my results will take some time. This thread is to document how I set it up and what I catch over time.
I installed the RX can just as the directions explained, but I routed the hoses differently. I left my UPR can right where itís been for months, but rerouted one hose. I left the hose from the passenger side of the engine to the inlet of the UPR can. Then a new hose from UPR can outlet, routed to the inlet of the RX can. The RX outlet hose goes back to the engine. The PCV exhaust now flows from the engine, through the UPR, then through the RX, and finally back up to the engine intake.
Before installing everything for the test, I cleaned the UPR can thoroughly. The bottom of the can (inside) was covered with a thin layer of stiff sludge that I could only clean out using gas. Iím glad that was caught, along with the ounces of oil, water, etc, over the months Iíve been emptying it. But I was surprised at the outlet hose from the UPR can. It was wet with oil. Obviously some was getting through the can and back to my intake. Iíve never let the can get close to half full before emptying it. Nearly every time Iíve emptied it, there was 1/4ď or less in the bottom. Iím noting this in case someone thinks I left the UPR get overfilled and it flowed through. Nevertheless, I started this test after cleaning everything for a fresh start.
I plan to leave this setup on for a thousand miles or so, and report my findings from each can.
1st picture: UPR can as it was originally installed.
2nd: CleanUPR can.
3rd: RX can installed. The hose in the top center of the can is the inlet. The outlet hose on the right has a check valve.
4th: Engine outlet to UPR inlet on left of can. UPR outlet on right side of can routed around (smaller hose) to the RX inlet. You can also see the other smaller hose coming back up from the RX can and ending at the intake on the engine.
Why not just hook up the RX can by itself and see it work. If you increase your volumn you have your answer. Why mess around the mumbo jumbo BS. You run the risk of not having a properly functioning PCV. The RX is designed to do the job properly Obviously you do not believe your other one works 100%. The traps work best when a filter/separator medium is added into them. You want the Vapor to condense in the trap and mostly air going to the intake. So get the empty one out of there for now. MHO
Not questioning your reasoning, just the design application. The sizes of your hoses seem way out of spec for the PCV system. Get them out of there and the right ones in place.