Code result
P0042
HO2S Heater Control Circuit
Moderate severity
What it means
Generic electrical fault in the heater control of the bank 1, sensor 3 oxygen sensor (typically a third sensor downstream of multi-stage cat or NOx trap).
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
Heater element open
highOne of the most commonly reported causes for this code — check this first.
Heater wiring or connector fault
mediumA plausible cause — test and verify before replacing parts.
Related help
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