P2195
O2 Sensor Signal Biased/Stuck Lean Bank 1 Sensor 1
Fuel & air metering
Generic OBD-II
Medium
What it means
P2195 means the upstream oxygen (air/fuel) sensor on Bank 1 is reporting a persistently lean mixture and isn't switching normally. That can be a genuine lean condition — an intake or exhaust leak, low fuel pressure — or the sensor itself biased and stuck. The car usually still drives, but it may idle rough, surge, and use a little more fuel until the cause is found.
Medium
Can I keep driving? Usually drivable — the car may idle rough, surge, or use a bit more fuel, but it's not a code that strands you. Fix it before it worsens.
Common symptoms
What you'll notice
- Check-engine light on
- Rough idle or engine surge
- Slightly higher fuel consumption
- Occasional hesitation
Common causes
Most likely first
- Exhaust leak near the sensor drawing in fresh air (false lean signal)Likely
- Failed or aged upstream air/fuel (O2) sensor stuck on a lean readingCommon
- Genuine lean condition — vacuum/intake leak or low fuel pressureCommon
- Dirty or restricted fuel injectorsLess often
- Wiring or connector fault in the sensor circuitLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame and live fuel-trim data to confirm whether the mixture is truly lean.
- Inspect for exhaust leaks near the upstream sensor and for intake/vacuum leaks.
- Check fuel pressure and injector condition if trims confirm a real lean condition.
- Inspect the sensor's wiring and connector, then replace the upstream O2/AF sensor if it stays biased lean.
- Clear the code and drive a full cycle to confirm the signal recovers.
FAQ
Quick answers
Is it safe to drive with P2195?+
Short-term, yes. A lean bias can cause rough running and higher temperatures over time, so address it before long trips or towing.
Can I just clear P2195?+
It returns once the sensor is monitored again unless the exhaust/intake leak, fuel issue, or failing sensor behind it is repaired.
Related codes
Often seen with P2195
Read & clear P2195 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX