my check engine light came on and it reads 02 sensor no activity. what does this mean?

Question

2007 Volvo s40 Bank 1 sensor 1 no activity

Answer 1

HI there,

Usually this means the front O2 sensor on bank 1 is no longer working. Most of the time the sensor itself is the problem. Making no contact inside the sensor. Replacing it will usually resolve the issue. If the engine is running very poorly it could cause the sensor to "stick" with one voltage, but most of the time the sensor itself is the issue.