Oh OK I changed exhaust and the fault still comes on after 30 minutes drive, also car seems developed some sort of problem. Acceleration is sluggish, what I mean when I accelerate hard the rev counter bounces between 2000rpm and 2100 for couple seconds than 2100rpm and 2200 and so on until gear changes and so on on EVERY gear. And I can feel it ! Also for some reason car doesn't show on dash exact gears. What I meant is when I'm in 6th gear and car reduces to 5 on hill (I can feel it and see it on rev counter) dash still shows 6th gear. Any idea what's going on?