i have a 2001 vectra sri 150 iv noticed over the past few weeks thats she's been using alot of oil and smokes a bit when u put your foot down,, runned fine till this weekend when i was going uphill and she just lost her power and she sounds like she's only running on 3 cilinders, when we cheacked the plugs they all looked burnt all for 1 which is the last on the right which was full of oil,, is the engine buggered or can it be saved?