Symptoms of P0184
- Check-engine light on, sometimes with rough or uneven running.
- Hesitation, surging, or a noticeable change in fuel economy.
- Occasionally hard starting or a smell of unburnt fuel.
Common causes of P0184
- A failing or contaminated sensor (MAF, MAP, oxygen or air-fuel sensor).
- Intake or vacuum leaks, or an exhaust leak near an upstream sensor.
- Wiring, connector, or fuel-delivery problems that skew the reading.
Useful checks before replacing parts
- Graph fuel temperature A during warm-up, vibration, hot soak, harness movement, and fuel pump operation.
- Inspect connector locking, terminal tension, corrosion, fuel contamination at terminals, harness rub points, and shared reference stability.
- Compare temperature jumps with fuel pressure, composition data, fuel trims, and freeze-frame operating conditions.
Related OBD-II codes
These nearby fuel / air entries can help compare wording and pin down the fault area.