That's a great result for the money. What was the main thing in that framework that actually clicked and helped you shut down the fight? Like, a specific step you hadn't been doing before.

Feel your pain on that one. Had to learn that lesson the hard way too.

But come on, is a loose oil cap actually a big deal? It just lets a little unmetered air in. Seen way worse stuff ignored for years without a rough idle. Maybe some cars are just super sensitive to the smallest thing. What model was it even?