A couple of months back I got an engine management light up on the dash, it stayed for a day then cleared itself. It had just been on a run after only doing short journeys for a month and the battery had been low on charge as well. As a result I put it down to the change in driving and a near flat Batt. Doing the same run the other night made it pop up again. This time I stuck the OBD reader on it and came up with the following :- o2 sensor Heater circuit Bank 2 Sensor 2 / System too lean Bank 2
I know that there is no guarantee that just because the car throws up a sensor issue that it is definitely the sensor, but in a drift in the right direction I am planning to replace the sensor. My problem now is that I dont know which side of the engine the 'Bank 2' refers to. Is it the drivers side of the car or the passenger side. Plus I have no idea how to identify which sensor is sensor 2. They never did a Haynes for the E46 325 Compact (or the other engine variants) so I am flying a bit blind.
So, where am I looking guys? and do I need a sensor with the longer wire or the short version? I keep seeing Pre cat and post cat, but no idea which has the right lead or where to find the one I am wanting to replace.