Got a P0137 code on your Vauxhall 1.0, 1.2, or 1.4? This guide explains location, causes, severity, costs, DIY fixes, and how to prevent future issues.
What Does the P0137 Code Mean?
The code indicates HO2S Circuit Low Voltage (Bank 1 Sensor 2). This means the ECU sees low voltage readings from the downstream oxygen sensor after the catalytic converter.
Where is O2 Sensor 2 Located?
Sensor 2 is positioned beneath the car, on the exhaust after the catalytic converter. Sensor 1, by contrast, is closer to the exhaust manifold.
Common Causes
- Exhaust leak before Sensor 2 (letting fresh air distort readings).
- Failed or aging downstream O2 sensor.
- Damaged wiring or poor sensor connections.
Severity of the P0137 Code
P0137 is a moderate severity issue. It won’t stop the engine immediately but may harm fuel efficiency and eventually the catalytic converter if ignored.
Can I Still Drive with the P0137 Code?
You can, but only for short distances. Prolonged driving may cause further damage to the exhaust system and increase repair costs.
How to Solve the Problem Yourself
- Scan the code using a diagnostic tool like the iCarsoft CR MAX BT.
- Inspect for exhaust leaks before Sensor 2.
- If no leaks, replace the downstream O2 sensor with an OEM part.
- Clear the code and confirm via a test drive.
How Much Does it Cost to Repair?
Repair costs vary: patching an exhaust may cost under $100, while replacing a genuine O2 sensor typically ranges $120–$250 including labor.
How to Fix the P0137 Code
Once repairs are done, clear the code using a scan tool. The CR MAX BT also displays live O2 sensor data to verify success.
How to Prevent the Occurrence of the P0137 Code
- Inspect exhaust pipes regularly for small leaks.
- Choose OEM oxygen sensors instead of aftermarket.
- Repair unusual exhaust noises early to prevent escalation.
Other Notes About the P0137 Code
If the code returns after repairs, double-check sensor wiring and exhaust integrity. Sometimes, intermittent wiring faults mimic sensor issues.
FAQs
Do I need OEM oxygen sensors?
Yes. OEM sensors give correct readings and last longer. Aftermarket parts often cause recurring error codes.
Which scan tool works best for Vauxhall error codes?
The iCarsoft CR MAX BT reads manufacturer-specific codes, live sensor data, and clears faults effectively.
Can a faulty O2 sensor damage my catalytic converter?
Yes. If the ECU receives incorrect readings, it may run a rich or lean mixture, leading to catalytic converter damage over time.
How long does it take to replace Sensor 2?
Usually between 30 minutes and 1 hour if the exhaust bolts are not seized. DIY replacement is possible with the right tools.
Will fuel economy improve after fixing P0137?
Yes. Once the sensor and exhaust are fixed, the ECU can manage air-fuel ratios more accurately, improving mileage.
Is P0137 related to other codes like P0138 or P0140?
Yes, these codes all point to downstream O2 sensor issues. If multiple codes appear, check wiring and exhaust leaks carefully.
Should I reset the ECU after repairs?
Clearing the fault code via a scan tool is enough. The ECU will relearn fuel trims automatically during the next drive cycle.
