P2244–P2248 O2 Sensor Reference Voltage Performance Bank 1 Sensor 1
The part responds, but not the way the ECU expects under these conditions - a wear or plausibility problem rather than a dead circuit.
Can you drive it? The engine light will stay on and the car may run in a reduced-power mode. Read the freeze-frame data to see the conditions the fault was logged under.
Which code is which
Same fault, different cylinder or bank — diagnosed the same way. Several set together usually means one shared cause.
| Code | Definition | Severity |
|---|---|---|
P2244 | O2 Sensor Reference Voltage Performance Bank 1 Sensor 1 | Investigate soon |
P2248 | O2 Sensor Reference Voltage Performance Bank 2 Sensor 1 | Investigate soon |
The definition
P2244: O2 Sensor Reference Voltage Performance Bank 1 Sensor 1.
P2244 is a manufacturer-specific powertrain code (the engine or gearbox). Its meaning is set by the carmaker rather than by the SAE standard, so a generic OBD-II reader will often show it as an unknown code or misread it.
What to check first
Cheapest and fastest checks first:
- Read the freeze-frame data stored with the fault - engine speed, load and temperature at the moment it logged tell you whether this happens cold, hot or under load.
- Check the connector at the part for corrosion, and that it is fully seated.
- Clear the code and see whether it returns, and under what conditions.
What actually causes this on a VAG
This is the same upstream wideband lambda sensor before the catalytic converter, on the cylinder 1 side. Unlike a straight open or short, "performance" means the reference circuit is present but its value is not what the ECU expects - a partial fault rather than a clean break. These are often intermittent, appearing only once the car is hot or over rough roads. The car usually still drives, with the engine light on and economy a little worse than normal.
Most likely causes, in order
- High resistance from corroded or strained connections. The best fit for this code and free to check. Green or dull pins, a plug that has taken water, or a crimp that has been pulled will let just enough through to look wrong rather than absent - which is exactly what a performance fault describes. Open the connector, inspect and clean it, and wiggle the lead with live data on screen to see the reading twitch.
- A poor engine earth. Also free, so do it before spending. Corroded or loose main engine and gearbox earth straps upset low-level sensor circuits and produce odd, drifting readings across several sensors at once. Clean the strap ends back to bright metal and re-tighten. If other sensors are reporting oddly at the same time, this moves to the top of the list.
- The wrong or a poor quality sensor already fitted. Costs nothing to check what is actually on the car. A superseded part, or a cheap sensor with a matching plug but a different internal calibration, will read close enough to run but not close enough to satisfy the ECU. If a sensor was changed shortly before this code appeared, verify exactly what was fitted before assuming the new one has already failed.
- The sensor's own reference circuit drifting out of specification. Wideband sensors carry internal reference and calibration resistances that can drift with age and heat, which reads to the ECU as a value present but out of range. This is the sensor-side cause that genuinely fits this code, and the only one on this list that costs money - so reach it after the three checks above. Fit a correct genuine sensor rather than a universal one.
Worth knowing: Performance and range codes are the ones most often "fixed" by fitting a sensor, only for the fault to return. Check the connector, the lead and the earths first, and if a sensor has been fitted recently, question its quality and part number before assuming the new one has already failed.
Reading the code is the easy part
A code names the circuit that complained. What tells you why is watching the sensor behind it while the engine runs — and that is where a code reader stops and a diagnostic tool starts.
VAGPULSE reads every module in a VW, Audi, Skoda or SEAT — not just the engine — shows the live measuring blocks behind this fault, gives you the freeze-frame conditions it was logged under, and clears it once you have fixed it. It also does what a generic OBD reader cannot on a VAG: service resets, coding, adaptations, and Stage 1–3 flashing with your original file saved first.
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Common questions
What does P2244 mean?
P2244 means O2 Sensor Reference Voltage Performance Bank 1 Sensor 1. The part responds, but not the way the ECU expects under these conditions - a wear or plausibility problem rather than a dead circuit.
Can I drive with P2244?
The engine light will stay on and the car may run in a reduced-power mode. Read the freeze-frame data to see the conditions the fault was logged under.