Help identifying these lines (solved, breather valves)

Driver's side, 3.4L 5vz-fe. Diagnosing a small EVAP leak, slowly replacing vacuum lines. Came across these two lines that are disconnected. I am not sure what they are for. Truck had one owner who did a lot of DIY work. Attached several pictures to try and help. Anyone have ideas?

Thanks!

 

Are you 4WD?

Edit: I see in your truck specs you ARE 4WD.

Those are most likely front differential breathers

 

Best I can tell from pics, those are breather/vent hoses….1 goes to your A.D.D. and the other one goes to Front Differential for your 4WD as noted in profile. Vent not vacuum hoses.

 

I see no vacuum lines.

Specifically which EVAP codes are you getting? As noted in the megathread, there are some common codes that point to specific things, and common causes for EVAP codes beyond what any diagnostic manual will tell you:

• Cracked fuel filler neck TSB for 2003-2004 trucks. See here. Causes P0441, P0442, P0446 EVAP codes. But also check the 'RODENTS' section two bullet points down for another possible cause. P0441 alone can be attributed to not-fully-twisted-until-click gas cap or faulty gas cap.
• RODENTS: Lots of plastics, wire sheaths, etc. in these trucks use soy-based plastics. If you have rodents nearby, or you park outdoors regularly, it's not uncommon for them to crawl in the opening under the intake manifold, where the starter & knock sensors live, and chew up the wiring (no start, knock sensor circuit codes). Likewise, they love nesting on top of the gas tank, and they'll chew up both the wiring like this, killing the pump (no start), and chewing up the tank tubes/plastics like this (EVAP codes, EVAP small leak, EVAP large leak). They'll chew through the gas filler neck, which will also throw EVAP codes, like this. It's common enough we can share exact photos of it, and there are more where those came from.

 

Learn something new everyday. Thank you very much!

 

Small evap leak. P0441 I think was the #.

Did the cap years ago, no change. The VSV/purge valve behind the engine wasn't working so I just swapped that out. Haven't cleared the code yet, but I'm curious to see if that did it.

 

It's possible, but that could also be something as stupid as a bad vacuum hose. Do you have a charcoal canister with lots of vacuum hoses sitting between your brake master cylinder and the battery? I think that stopped in 2003, maybe it's a 2000-2002 thing only.