I just replaced the o2 sensor in my car, let it sit overnight with the battery unplugged to reset the ecu. There were a couple of fellas on here that read my original post when I failed emissions. The exhaust was outputting a decent amount of whispy white smoke and smelled like gas. Just really looking for some confirmation here. Now with the new o2 sensor in, I turned the car on, small amount of white smoke.. left it to idle for about 10 minutes. Came back, no white smoke, no petrol odour. Took it for a good lashing, found that it has a lot better acceleration and more life in general. This would lead me to assume that it was indeed the o2 sensor that was broken and causing these symptoms, and I can now rest assured that I have solved the emissions issue? One can conclude from this that my o2 sensor was in fact broken and in replacing it, i will now pass emissions? I've never had to troubleshoot emissions in a car before, so please bear with me. Thanks ahead of time.