Vauxhall Zafira spark plugs gone black

hi becki its erin its worth while getting your spark plugs changed as that is what the problem is had another garage look at mine and the cat converter is fine put new coil pack and spark plugs on and it seems fine

If they are black it means the fuel mixture is too weak, the air mass sensor or fuel pump could need looking at. If the car is diesel watch for black smoke out the exhaust when revving it, this would indicate too little air getting through