Our auto-blog has shipped 15 OBD-II fault-code guides, each one a detailed diagnostic ladder rather than a one-liner definition. Covered so far:
Cam/crank correlation: P0017 MAP & sensor circuits: P0107, P0120 O2 sensor (Bank 1 Sensor 1): P0131, P0132, P0134 O2 sensor (Bank 1 Sensor 2): P0141 Fuel trims: P0172, P0174, P0175 Fuel rail pressure: P0190 Turbo: P0299 Misfires: P0300, P0303, P0304
Each post follows a fixed structure: what the code actually means in plain English, the top 4-5 likely causes ranked by what shops actually see, what to check first with a basic OBD-II reader, what shows on a live scan, and when to stop DIY and call a specialist.
The content is also republished on Dev.to with a canonical tag pointing back to obd2.online — Google credits us as the original. That gives us 30 indexable surfaces (our pages plus the canonical-tagged copies) covering the same topic cluster.
Next batch in the queue: P0420 (catalyst efficiency), P0440/P0455 (EVAP system), P0500 (vehicle speed sensor), and the full P03XX misfire range. At the current rate the next 50 codes ship over the coming months.