P2197 on Toyota
O2 Sensor Signal Biased/Stuck Lean (Bank 2, Sensor 1)
P2197 on Toyota vehicles indicates o2 sensor signal biased/stuck lean (bank 2, sensor 1). Au7o has documented this code across 2 Toyota models — most commonly on Camry, Highlander. The PCM detected that the upstream (sensor 1) oxygen/air-fuel sensor on bank 2 is stuck reporting a lean signal and is not responding to mixture changes. The bank 2 sensor signal is biased lean and unresponsive. Typical repair costs on Toyota range from $220 to $600, depending on the specific model and root cause.
Common Causes of P2197
- •Failed/aged upstream O2 (A/F) sensor bank 2
- •Exhaust leak near bank 2 sensor
- •Actual lean condition (vacuum leak, low fuel pressure)
- •Contaminated sensor
- •Sensor wiring/connector fault
P2197 on Toyota by Model
Toyota Camry(1 issue)
- 2007-2010 2GR-FE P0138/P0158/P0606 Diagnostic Gates - T-SB-0001-102007-2010
Toyota T-SB-0001-10 Rev1 covers specified 2007-2009 Camry VDS BK46K and 2010 VDS BK3EK applications. P0138/P0158 may result from incorrect air-fuel-sensor response, and P0606 may also be present due to incorrect downstream O2-sensor operation. Toyota distinguishes these paths using the complete DTC set, freeze-frame air-fuel/O2 voltage and downstream O2 impedance, followed by circuit inspection. It does not describe every P0606 as a sensor fault or support the original 2AZ-FE, 2006-2012, VSC/TRAC or battery claims.
Toyota Highlander(1 issue)
- Air/Fuel Ratio Sensor Signal Stuck Lean — P2195 / P2197 with P0138 / P0158 (2GR-FE)2008-2013
Second-generation Highlanders with the 2GR-FE V6 commonly set a check engine light for an upstream air/fuel ratio sensor whose signal sticks on the lean side of its range. The characteristic Toyota pattern is a downstream oxygen sensor circuit-high code (P0138 bank 1 or P0158 bank 2) appearing together with, or instead of, the A/F sensor code (P2195 bank 1, P2197 bank 2) — the ECM flags the rear sensor because the front sensor's slow response drives the fuel trim, so shops that replace the downstream O2 sensor first fix nothing. Toyota published a service bulletin covering 2008-2010 Highlander for exactly this combination, attributing it to incorrect air/fuel ratio sensor response. Symptoms are mild — a light, slightly worse fuel economy, occasional rough idle — but the car will fail emissions testing.
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View P2197 across all makes →Frequently Asked Questions
What does P2197 mean on Toyota?▼
P2197 stands for "O2 Sensor Signal Biased/Stuck Lean (Bank 2, Sensor 1)." The PCM detected that the upstream (sensor 1) oxygen/air-fuel sensor on bank 2 is stuck reporting a lean signal and is not responding to mixture changes. The bank 2 sensor signal is biased lean and unresponsive. On Toyota specifically, this code is documented across 2 models.
What causes P2197 on Toyota vehicles?▼
Common causes on Toyota: Failed/aged upstream O2 (A/F) sensor bank 2, Exhaust leak near bank 2 sensor, Actual lean condition (vacuum leak, low fuel pressure), Contaminated sensor, Sensor wiring/connector fault. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P2197 on a Toyota?▼
Repair costs on Toyota range from $220 to $600, depending on the specific model and root cause.
Which Toyota models have P2197 documented?▼
Au7o has documented P2197 on 2 Toyota models: Camry, Highlander.