They didn’t change “to” HLAs but “from” HLAs in 1997.
95 and 96 HLA
97 and up is not
This is all well known by folks mechanically familiar with EJ22s. There’s a couple of imprecise 97 transitions or caveats but they haven’t even come up in this thread yet
It’s mostly confusing like any other car info because people who owned three Subarus with very little EJ22 experience comment anecdotally and make incorrect assumptions. after all these decades the cars may not have their original engines or the year engine the current driver was “told” or “remembered” in it. people search and regurgitate inaccurate info. Wash rinse repeat, internet convinces thousands. I hear so much bad info when people call or ask me in person and tell me what they read online. it’s not worth my time to listen to what they read online, it’s more confusing and wasteful trying to explain or counter or include that in an actual diagnosis…easier for me to ask lots of questions and diagnose myself.
Most of the other Subaru forums are filled with inaccurate info and ensuing messiness. It’s a nightmare trying to participate in them for accurate high level information unless you can recognize the few users who are good. And most people can’t because they don’t know enough to know the difference. They’re nice for “community” whatever that means “online” but otherwise I find them annoying, though I’m admittedly practical and have an engineering background to a fault when it comes to Subarus.