Hi

My Car is running a bit sluggish but not too bad except when i go onto the motorway and after a few miles when i try to accelerate the car goes into limp home mode with the cogand exclamation mark warning light on ,

on looking around the engine i found a carbon like soot under the air fliter box and around the back of the engine , i have since changed the oil and all the filers also tryed a injector cleaner but still no change what should i try next .

Thanks