Check Engine Code
P2197
O2 Sensor Signal Biased/Stuck Lean — Bank 2, Sensor 1
What P2197 means
P2197 means the front (upstream) oxygen sensor on Bank 2 is stuck reporting a lean mixture. Either the exhaust really is lean on that bank, or the sensor/wiring can no longer swing rich — so the ECM can't trim fuel correctly.
Symptoms
- Check engine light on
- Rough idle or slight misfire
- Reduced fuel economy
- Occasional hesitation on acceleration
Likely causes (most common first)
- Intake or vacuum leak on Bank 2 (unmetered air)
- Faulty upstream O2 / air-fuel sensor on Bank 2
- Exhaust leak ahead of the sensor
- Low fuel pressure or a weak fuel injector
- Dirty MAF sensor skewing the fuel calculation
Can I keep driving?
Yes, short-term. Fix it before long trips — a persistent lean condition can overheat the exhaust and damage the catalytic converter.
Typical repair cost
DIY fixes can start near $50 (parts only). Shop repairs for P2197 typically run up to $400 depending on the underlying cause and vehicle. Start with the most common cause — Intake or vacuum leak on Bank 2 (unmetered air) — before throwing parts at it.
Recommended parts & tools for P2197
Our buyer’s guides cover the tools and parts that pair with AXLY:
As an Amazon Associate, AXLY earns from qualifying purchases.
Related codes
Confirm P2197 yourself in 60 seconds
Two cheap things and you can read P2197 yourself — plus every other stored code and live engine data, free. No subscription.