P2270 is a general DTC trouble code, which means it has the same meaning for the Opel Signum as it would any other vehicle. It means that the oxygen sensor located on bank 1 behind the catalytic converter is continuously sending voltage that indicates a lean air/fuel mixture.
This does not necessarily mean that your Signum is running lean (although it can). It’s usually caused by a bad oxygen sensor, or an exhaust leak.
How to Find Bank 1 Sensor 2
There are oxygen sensors on both sides of your Signum’s catalytic converter(s). This lets the ECM read the exhaust before and after it has run through the catalytic converter to make sure that it is functioning correctly (for emissions purposes).
Here’s what P2270 means, and how to find Bank 1 Sensor 2.
P2270: O2 Sensor Signal → Biased/Stuck Lean (Bank 1 | Sensor 2)
- Bank 1 is the side of the engine with the first cylinder. If your Signum has a four cylinder engine, you don’t have to worry about this, as there is only one cylinder head. If you happen to have more than one cylinder head, you will need to look up where cylinder one is for your particular engine. P2272 affects bank 2.
P2270 Symptoms: Opel Signum
There are usually no symptoms associated with P2270. The code is indicating that the signal coming from your Signum’s downstream oxygen sensor at B1S2 is leaner than it should be. The signal from the oxygen sensor upstream of the catalytic converter does not agree with the lean condition indicated by the downstream oxygen sensor. If it did, you’d have P0171.
There are usually no drivability issues when P2270 appears by itself.
Opel Signum: P2270 Causes
Here are some of the more common causes of P2270 in the Opel Signum.
Exhaust Leak (Highly Likely)
Oxygen Sensor (Highly Likely)
- Low fuel pressure
- Loose O2 sensor
- Bad fuel injector at bank 1
- Bad purge valve
- Bad PCM
Conclusion: P2270 Opel Signum
It’s normally the oxygen sensor that needs replaced when P2270 appears in the Signum. But, there can be other issues as well. Good luck diagnosing the code.