P2198

O2 Sensor Signal Biased/Stuck Rich Bank 2 Sensor 1

Q: Is it safe to drive with P2198?

Short term, yes. But a rich mixture wastes fuel and can overheat and damage the catalytic converter over time, so address it before long drives.

Q: Can I just clear P2198?

It returns until the sensor or the underlying rich condition is fixed, since the ECM keeps checking the bank 2 sensor's signal.

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

What it means

P2198 means the upstream oxygen (air-fuel ratio) sensor on bank 2, sensor 1 is reporting a signal biased or stuck toward rich. That can be the sensor itself failing, or a real rich-running condition the sensor is correctly seeing. The engine stays drivable but may idle roughly and use more fuel, and prolonged rich running can harm the catalytic converter.

Medium

Can I keep driving? Drivable, but the mixture may be running rich — expect worse fuel economy and possible rough idle, and long-term rich running can shorten catalytic converter life.

Real-world scan data

Seen in

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 or uneven idle
Increased fuel consumption
Engine surging

Common causes

Most likely first

Faulty upstream O2 / air-fuel ratio sensor (bank 2, sensor 1)Likely
Sensor wiring open, shorted, or contaminatedCommon
Poor or corroded connection at the sensorCommon
Genuinely rich mixture — high fuel pressure or a leaking injectorLess often
Exhaust or intake leak skewing the readingLess often

How to diagnose & fix

Work through it in order

Read freeze-frame and view the bank 2 sensor 1 signal; a stuck-high/rich trace confirms the bias.
Inspect the sensor connector and wiring for damage, corrosion, or exhaust contamination.
Check fuel trims and fuel pressure to rule out an actual rich condition before condemning the sensor.
Look for injector leakage and for intake/exhaust leaks near the sensor.
If fueling is normal and wiring is good, replace the bank 2 sensor 1 O2/air-fuel sensor and retest.

FAQ

Quick answers

Is it safe to drive with P2198?+

Short term, yes. But a rich mixture wastes fuel and can overheat and damage the catalytic converter over time, so address it before long drives.

Can I just clear P2198?+

It returns until the sensor or the underlying rich condition is fixed, since the ECM keeps checking the bank 2 sensor's signal.

Read & clear P2198 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