Posts Tagged: Oxygen Sensor Circuit Slow Response

P0133 Code — What it means and the most common causes

Learn what a P0133 code means, the most common causes and how to fix it A P0133 code is defined as: 02 Sensor Circuit Slow Response (Bank 1 Sensor 1). Bank 1 is the bank that holds cylinder #1 and sensor 1 is the sensor upstream from the catalytic converter. The code means that the upstream oxygen sensor on the exhaust from bank 1 isn’t reacting as quickly as it should to changing oxygen levels. The ECM is constantly updating the air/fuel mixture and overshooting and undershooting the 14.7:1 ratio. … Read More