I had ordered an 02 sensor from GSF, i checked the part and i specifically ordered a premium part, after it arrived it turns out it was just a standard delphi 02 sensor, same product code but i was under the impression i would receive a denso part. Anyway after opening it, the part had no anti sieze compound on threads, so had to source some, it did install easily enough, and the car didn't sound any worse. Then after driving for about 15 mins the engine management light came on, i plugged in my obd2 scanner and it showed up a fault with the voltage sensor wire (it had no voltage). So because of this issue, car was using masses of fuel. I got home and replaced the sensor with the older sensor that i had removed. Same issue i had before removing it but at least it showed some voltage. Will now have to fork out god know what to rectify issue, seeing as part has been used i doubt gsf will accept a return for a refund. Not the best shopping experience but you live and learn.