Code result
P01F5
O2 Sensor Circuit No Activity Detected Bank 1 Sensor 4
Moderate severity
What it means
Bank 1 sensor 4 O2 sensor shows no signal change despite operating conditions that should produce activity. 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
Sensor dead or unheated
highOne of the most commonly reported causes for this code — check this first.
Related help
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