O2 Sensor No Activity Detected Bank 1 Sensor 2
The engine computer is not seeing the rear oxygen sensor on Bank 1 change as expected. This usually means the sensor, wiring, or exhaust conditions are preventing a normal signal. It can also be caused by an exhaust leak or fuel mixture problem.
The vehicle is usually drivable, but the problem should be diagnosed soon. Fuel economy may drop and the emissions system may not work correctly.
P0140 means the PCM detected little or no switching activity from the Bank 1 Sensor 2 oxygen sensor. This is the downstream O2 sensor, usually located after the catalytic converter on the bank that contains cylinder 1. The code points to a sensor signal problem, wiring fault, exhaust leak, or less commonly a catalytic converter or engine operating issue affecting the signal.
It refers to Bank 1 Sensor 2, the downstream oxygen sensor located after the catalytic converter on the bank with cylinder 1.
Yes, but it is less common than a failed sensor or wiring issue. Exhaust leaks and sensor faults should be checked first.
It can, but not always. The downstream sensor mainly monitors emissions performance, so many vehicles show little drivability change.
Not always. Inspect wiring, connectors, and exhaust leaks first because those problems are common and can cause the same code.