Severity: Fix soon. Usually safe to drive for now.
The first oxygen sensor on bank 1 is reacting too slowly to changes in the exhaust, so the computer cannot keep the air-fuel mix steady.
Replace the oxygen sensor — a slow response almost always means the sensor itself is worn out.
Usually just a check-engine light and slightly worse fuel economy.
Generally safe to drive, but get it checked soon. Usually just a check-engine light and slightly worse fuel economy.
The most common causes are: Aging or contaminated oxygen sensor; Exhaust leak; Failing sensor heater; High-mileage sensor past its service life. A scan tool and a visual check of the parts above is where a technician starts.
Replace the oxygen sensor — a slow response almost always means the sensor itself is worn out.
