Engine light

[AlpinaJr]

Hi, Having attended Zedfest yesrerday & giving my Alpina RS a long overdue run out covering 350 miles in total. I noted my engine light came on within the last 10 miles of my journey. I pulled over & turned the ignition off & on & the light was no longer. I then ran a engine check through on Carly & it came up with error code/description 000E4 Lambda regulator deviation bank 2. For the record my Alpina flew through its MOT last week & ran like a dream over the weekend. So unsure what the issue is but the light has not returned in the last 24hrs.

[colb]

Exhaust sensor code indicates its not working correctly hence it setting the EML. If you have diagnostics that can read live data take a look at each of the sensors on Bank 2 and see what they are doing in graph form. The pre cat sensor should be producing a rising and falling wave form as the voltage scans up and down, do this with a fully warmed up engine in closed loop so the sensor is being monitored by the engine computer. The post cat sensor when viewed should be quite static it will react if it sees unburnt fuel in the exhaust and react accordingly in graph view. Most common fault with pre cat sensors is the heating circuit inside them burning out, replacement should be oem brand, Bosch is the best bet as they come with the correct plug in connector, don't use the universal type that has to be wired in.