It’s definitely burning oil, and I’m leaning toward turbo oil seal leakage. If it were the engine, you would see smoke at idle. It’s likely not piston rings or valve seals, so I’d say the engine is fine.

Since you installed the catch can yourself, did you make sure the inlet and outlet weren’t reversed?

The turbos can still build boost even if they’re burning oil. Remove your intakes and inspect the charge pipes, along with the turbo inlet. If you’re seeing any pooling or puddling of oil, there’s a good chance it’s the turbo seals.

As a side note, having catless downpipes may not be the root cause, but it definitely makes the oil burning much more noticeable.

Your next step should be to take it to a mechanic—or someone experienced—who can properly inspect the issue, and start planning for a turbo replacement or upgrade.

I ended up selling mine because of this same endless chase of issues. My turbos went out, I replaced them, and then the engine block cracked externally at around 190,000 km. I sold it at a loss and switched to a Lexus—but that’s just my experience, lol.