P2197

O2 Sensor Signal Biased/Stuck Lean Bank 2 Sensor 1

Q: Is it safe to drive with P2197?

Short-term usually, but running lean or rough wastes fuel and can raise emissions, so have it diagnosed soon.

Q: Can I just clear P2197?

It clears, but returns unless the underlying lean condition, wiring, or sensor is repaired.

Fuel & air metering (O2 sensor) Generic OBD-II Medium

What it means

P2197 means the upstream (sensor 1) oxygen sensor on bank 2 is reporting a signal that's biased or stuck lean — it isn't swinging the way the PCM expects. It can be the sensor itself failing, or a genuinely lean mixture from an intake/vacuum leak, exhaust leak, or fuel-delivery problem. The car usually still drives but may run rough and burn more fuel until it's diagnosed.

Medium

Can I keep driving? Usually drivable, but a stuck-lean signal can cause rough running and worse economy — fix it soon to avoid drivability and emissions issues.

Real-world scan data

Seen in

115

scans in the past year

Found in

<0.1%

of scans

<0.1%

of scans that found faults

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

Common symptoms

What you'll notice

Check-engine light on
Rough idle or running
Engine surge or hesitation
Reduced fuel economy

Common causes

Most likely first

Faulty upstream (sensor 1) oxygen / air-fuel sensor on bank 2Likely
An actual lean condition — vacuum/intake air leak on bank 2Common
Exhaust leak upstream of the sensor drawing in airCommon
Low fuel pressure or a weak/clogged injectorLess often
Sensor wiring open/shorted or a poor connectionLess 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 or the signal is stuck.
Inspect bank 2 for intake/vacuum leaks and check for exhaust leaks near the sensor.
Check fuel pressure and injector operation if trims show a real lean condition.
Inspect the sensor's wiring and connector for corrosion or damage.
If the mixture is correct but the signal stays stuck lean, replace the bank 2 sensor 1 O2 sensor.

FAQ

Quick answers

Is it safe to drive with P2197?+

Short-term usually, but running lean or rough wastes fuel and can raise emissions, so have it diagnosed soon.

Can I just clear P2197?+

It clears, but returns unless the underlying lean condition, wiring, or sensor is repaired.

Read & clear P2197 yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

▶ Get it on Google Play

✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX