If anyone here is using the AEM 30-4110 wideband I have the 02 sensor that you can have for free. It's used but I'm sure it still works, it's the NGK brand which is supposed to be better than the stock 02 you get with the unit. My 4110 head died and I hate to throw out the 02 so I'd rather see one of you use it, even if you just want it for a back up.