I have a 2020 Golf. Last month, the check engine light suddenly came on. I went to a repair shop, and the mechanic immediately suggested replacing the entire throttle body assembly.
Instead of rushing into expensive repairs, I borrowed an ELM327 scanner and used OBDocker to diagnose it myself. The scan revealed fault code P2188 (System Too Rich at Idle), with abnormal long-term fuel trim values.
After some quick research, I suspected it was just a dirty Mass Air Flow (MAF) sensor. I bought a cleaner for about $15, removed the sensor, sprayed it down, and reinstalled it. The check engine light went off immediately, and the car has been running perfectly ever since.
I avoided a potentially hundreds-of-dollars repair bill for a simple cleaning. Totally worth it! This app is super convenient for quick diagnostics and peace of mind. Just wanted to share in case anyone else faces this issue.