Code result
P2271
O2 Sensor Signal Stuck Rich
High severity
What it means
The downstream oxygen sensor on bank 1 reports a constant rich signal during a forced-lean command. Suggests a failed downstream sensor or a sensor contaminated by oil/coolant from upstream engine wear.
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 rich
highOne of the most commonly reported causes for this code — check this first.
Downstream sensor contaminated
mediumA plausible cause — test and verify before replacing parts.
Related help
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