Code result
P2270
O2 Sensor Signal Stuck Lean
High severity
What it means
The downstream oxygen sensor on bank 1 reports a constant lean signal during a forced-rich command from the ECU. Suggests either a sensor that has lost its rich-side response, or a catalyst that is so degraded that no rich exhaust reaches the downstream sensor (cross-check P0420).
Is it safe to drive?
No — stop driving
This code points to a problem that can cause damage or affect safety. Avoid driving and have the vehicle diagnosed promptly.
Most likely causes
Downstream sensor failed stuck lean
highOne of the most commonly reported causes for this code — check this first.
Exhaust leak after catalyst
mediumA plausible cause — test and verify before replacing parts.
Related help
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