DTC Description
ECM shows P2237 when the conditions are like below.
- Deviation of average correction value of fuel ratio is higher than 0.1 when sensor voltage is 1.49~1.5V
- Accumulated air mass flow value is higher than threshold value when target lambda is 0.97
- Upstream O2 sensor displays 1.7V below when the fuel cut is being kept over 3 minutes.