Severity: Fix within days. Drive with caution and watch for new symptoms.
The first oxygen sensor on bank 1 is stuck at a low voltage, which the computer reads as a lean mixture even when the mixture may be fine.
Check for vacuum and exhaust leaks and low fuel pressure, then replace the sensor if it stays stuck low.
The engine may run lean and hesitate. Drivable with care, but do not ignore it.
You can drive short distances carefully; watch for worsening symptoms. The engine may run lean and hesitate. Drivable with care, but do not ignore it.
The most common causes are: Failed oxygen sensor; Vacuum leak; Low fuel pressure; Exhaust leak before the sensor; Wiring short. A scan tool and a visual check of the parts above is where a technician starts.
Check for vacuum and exhaust leaks and low fuel pressure, then replace the sensor if it stays stuck low.
