Ok I put on my o2 sensor yesterday and my check engine light went out. I have a p72 gsr ecu...now i know the ecu looks for a knock sensor but i never got a check engine light for not having one...so yesterday when i put the o2 sensor in the check engine light for the o2 went out...after driving for a few minutes the light came back on with o2 and knock sensor...would the knock sensor throw off the o2? The other thing is that as I am driving the check engine light goes away and comes back after a few minutes...any ideas?

 

Knock sensor won't throw a code for the o2. As for the light coming on and off, I think it's due to the o2 code, you may have a vacuum leak which cause the o2 to send a lean signal to the ecu which it can't correct then you step on the gas, the o2 voltage switches again and the light turns off.