Hi guys, Got a question here. Last week when I got my ute serviced I got my mechanic to change the o2 sensor (before the cat) with this o2 sensor. http://www.ebay.com.au/itm/OXYGEN-SENSOR-O2-SENSOR-4-WIRE-FORD-/360361045267?pt=AU_Car_Parts_Accessories&hash=item53e7312d13 Soon after I got the ute back when it's cold and warming up (as I do religeously) it's running rough, not quite stalling but close. Its also blowing alot of black smoke out the tailpipe. It's turned the engine light on a few times now, showing the usual catalytic converter code. Strange thing is, once it's warm it runs fine. I've checked the packaging, its from a company called HIFLO in Springvale, all the wiring looks exactly the same as the original. The sensor itself is slightly different with more of those holes running through it but is marginally smaller. I've called them and they say its not a mistake that is the correct part number for this car. Even the ebay add says they've sold 40 of them. Does anyone know for sure if the o2 sensors in the BF's are the same before/after the cat? Thanks guys, Jarrod.