Code result
P01F3
O2 Sensor Circuit High Voltage Bank 1 Sensor 4
Moderate severity
What it means
Bank 1 sensor 4 O2 sensor signal voltage above expected range — short to power or sensor stuck high. A drifted or sluggish lambda sensor lets the mixture run lean or rich without correction — fuel economy and emissions suffer immediately.
Is it safe to drive?
Use caution
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical.
Most likely causes
Signal wire shorted to battery
highOne of the most commonly reported causes for this code — check this first.
Connector pins corroded - high contact resistance
lowLess common, but worth ruling out after the more likely causes.
Supply wire pinched against B+ source
lowLess common, but worth ruling out after the more likely causes.
Related help
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