It could be that or there's a possibility the pins in the plug/connector aren't making contact. I'd check continuity across that junction. There's also the possibility the engine is just not running right causing the oxygen sensor to trip the check engine light. (meaning the sensor is fine but the engine just needs a tune-up)Pete said:Hmmm, but if the sensor I installed is brand new than do you think it's faulty?
Before replacing parts, always check the condition of all other related parts. Example: spark plugs, cap, or rotor are very worn causing insufficient spark. This leads to some of the air/fuel mixture not being burned. The oxygen sensor will pick up on this and trip the CEL.