I have read quite a bit into this and know it could be one of many things...MAF Sensor, O2 Sensors or Vacuum Pipes. A little background:
I diverted the pipework past the N249 valve the other night because the car had started to become a little slugish, it had perked up slightly however a couple of day later I get the following error code (17536 - Fuel Trim Bank 1 (Mult): System too Lean).
I had a little inspection tonight (couldn't sleep!!!) and found a worn pipe, however it's connected to an item on the fuel rail (drawn around it in red in the image attached - i think it's a fuel pressure regulator?). The pipe was quite a little loose, could this be causing the fault code?
Are there any other tests I could perform? Your help is really appreciated as I'm driving to Loughborough this weekend!!!