90% of problems on modern cars are computers miscommunicating with other computers, out just deciding that some sensor isn't behaving well enough, so you have to throw the baby out with the bath water. All this in proprietary formats in proprietary subsystems a filthy mortal like you can't afford the tools to even know what's wrong.

How do I read the knock sensor info from OBD port for Subaru

A: It's not part of the OBD standard, so you need a Cobb access port to read the data

Okay but I don't have money for that and I'm literally just making a python script to do this.

A: Well you need the custom ID to query the sensor info

Okay what's the custom ID?

A: You have to pay morbillion dollars to get access to the documentation that has the custom info that you can get from the ECU

Not even close to doing anything with tuning ot modding, but you're telling me I can't even read a sensor because neither Subuaru nor Cobb will tell me a single hex ID bruh

I just wish I could but a fucking service manual. Seems like like the only way is to get access to a digital copy through a subscription service. I don't need service manuals for every car made, just mine.