Could someone look under their hood and see if these three "vents" are supposed to be open to the atmosphere, or should they have hoses or plugs connected to them. Thanks.
Are those the standoffs for a decorative cover that sits on top of the engine, that might be missing on yours?
Those are indeed the places where an engine cover goes. The cover has rubber rings that hold onto those tubes. But the M20A in the Prius sits too far under the cowl for any engine cover to fit. The only M20A I found that uses a cover is the Lexus UX series. Back in 2023 when I bought my gen5, I ordered one to see if it would fit. If it had, I was going to modify it a bit to remove the Lexus badging and replace it with Toyota badging. But it only took a few minutes to realize the plans were futile. There are only three connection points, and one is right under a heat shield(the one in OP's first photo). There's no way to modify the engine cover to fit without removing that connection entirely. And the cover wouldn't be stable with only two connection points. So now I've got a UX 200 engine cover sitting on a shelf in my garage for the last three years. lol As for why the Prius(and Corolla) valve cover has points for a engine cover it doesn't have, it's because it's cheaper to just make a single part that works on all M20A engines. This is what the M20A in a UX looks like: I bought a UX 200 cover that didn't have the hybrid badge. I planned to paint the whole thing one or two shades of matte black for more of a Toyota look, and I was going to pry or grind off the Lexus L and find a chromed Toyota T logo of about the same size and glue it on. I believe it was the gen3 where you could dress up the engine bay with parts from Toyota Japan as well as some parts from the Lexus CT(OEM hood struts, coolant tank covers, engine cover, etc.). I was hoping to do something similar to my gen5, but the spaces are just too tight.
