Symptoms of P0094
- 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 P0094
- 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
- Monitor fuel pressure command, actual pressure, low-side supply, pump duty, regulator command, and injector balance if supported.
- Inspect fuel lines, filter housing, pressure regulator, pump module, rail pressure sensor, and return or leak-off paths where applicable.
- Check whether pressure decay happens after shutdown, during hot restart, at idle, or under moderate acceleration.
Related OBD-II codes
These nearby fuel / air entries can help compare wording and pin down the fault area.