Hi, I've just bought a 2005 golf plus 1.9tdi, all was well until it started running rough and smoking.I pulled the plug from the maf sensor and it started running fine again.I fitted a new sensor, plugged it in and it's running rough again. I was thinking maybe it's the wiring but I don't know what the voltage etc should be, or could it be something else, if anyone has any ideas id be grateful.