I need the part number for thw lambda sensor/probe please. I went to VW but they got all confused and couldnt tell me which 1 I needed out of the 4 that came up on the screen. The mk3 is overfuelling and backfiring and its costing me a fortune. The probe isnt even int he exhaust so rather than clean it and put if back in, just gunna get a new sensor, cos it looks like its past its time (was like this when I bought the car, but I only noticed the other day when I was cleaning the engine bay). Could it have casued any damage wiht it not having the probe plugged in? Thanks