My car poped the CEL recently. I sprayed the sensor with CRC Cleaner but I still get the OBD II faults 170 and 173 ( fuel trim ) after about 8 cycles. The car ran great though. To solve this I bought a sensor on ebay, $80.00 fit right, looked OK, smelled funny and the car ran poorley. almost stalled on start and did not shift?? correctly, also the idle RPM was low, about 500 or lower. The lesson to be learned buy OEM. I wonder how long it will take me to learn that lesson.