Modern vehicles are essentially rolling computers. When a check engine light...
https://tiny-wiki.win/index.php/Why_Your_Shop_Needs_Serious_Diagnostics_for_Emissions_Compliance
Modern vehicles are essentially rolling computers. When a check engine light pops on, basic OBD readers only give you a surface-level code. To actually fix the car, you need to talk to every ECU and view live data streams while the engine runs