Okay so here's the story, I did my timing belt & water pump and I threw on new ignition wires and spark plugs and then my check engine and vsc / vsc off lights came on. I pulled the code for the check engine and it came back as p0154 no circuit activity from bank2 sensor1 o2 sensor so I did the most logical thing... I changed the sensor! So I drove the car home and the lights came back on! Because I know its possible, I swapped out the sensor with a brand new one (denso if you're wondering) thinking it may be defective... nope light came back on the drive home with same code! Can anyone help me out, I'm confused and frustrated! Thanks for the help guys!

 

you should try changing the bank 1 sensor 1 o2 sensor as well. i had a similar problem as you do two years ago. i changed the sensor that the code said was defective but the code still persisted. so my mechanic finally changed the other front, pre-cat o2 sensor and the code went away.

good luck. hope that helps.