Severity: Fix within days. Drive with caution and watch for new symptoms.
The computer is getting no usable signal from the first oxygen sensor on the side of the engine with cylinder 1, so it cannot fine-tune the air-fuel mix.
Check the wiring and exhaust for leaks, then replace the sensor if it gives no signal.
Fuel economy drops and the engine may run rough. Drivable with care.
You can drive short distances carefully; watch for worsening symptoms. Fuel economy drops and the engine may run rough. Drivable with care.
The most common causes are: Failed oxygen sensor; Damaged wiring or connector; Exhaust leak near the sensor; Blown fuse for the sensor heater. A scan tool and a visual check of the parts above is where a technician starts.
Check the wiring and exhaust for leaks, then replace the sensor if it gives no signal.
