 We replace valve covers on lots of cars. Never had to do it on a Subaru for this problem, but we have on many Silverado trucks. And sometimes they'll tell me, it burns oil on the highway, but it doesn't burn oil when I drive it in town. Like, yeah, you've got a valve cover problem for sure. So we pop off that driver's valve cover and replace it with like a Dorman Products updated one that has the updated baffles, and it's gone. It's just like, oh, they told me I needed an engine. No, you don't. You need a valve cover.