A fault code doesn’t yet mean the unit or sensor itself is faulty: often it’s the plug and connector leading to it.
Possible causes
- Air leak: cracked hoses, intake gasket, vacuum hose, PCV valve
- Weak fuel pump or clogged fuel filter
- Dirty injectors
- MAF sensor reads low
What you can do yourself
- Listen at idle: a hissing sound means an air leak.
- Look at the fuel trims on the “Sensors” tab.
- Check the fuel pressure.
Stop and don’t drive on if:
- The Check Engine light is flashing
- The temperature gauge is in the red or the overheating light is on
- The red oil pressure light is on
- Smoke from under the bonnet, a burning or petrol smell
- Strong jerking, knocking from the engine, or the car barely moves
OA case from Oleg’s practice
- Changan CS55 Plus Check Engine on, code P217700 — lean mixture off idle. Given the 74 000 km mileage, we recommended checking and, if needed, replacing the fuel filter and checking the injectors, rather than replacing parts based on a single code. How it went ↗
The explanation comes from the error code reference in the AvtoElektrik PRO app.