ive had my uk 99 turbo for about 3 weeks now, all was fine when i first got it,but then it started stuttering. holding a steady throttle in any gear at about 2000 rpm it judders slighlty and when you put your foot down it stutters before the turbo kicks in then it would be fine, been reading on here about maf sensors etc, so brought a new and cleaned the boost solonoid. the stuttering has nearly almost gone, but now when the turbo kicks in it seems like its holding back. from 3000 to 5000 rpm it stutters a bit and hesitates. now done the diagnostic test and i think it showing 32. oxygen sensor. reset the ecu and the code appears again. would a faulty o2 sensor cause this? car is standard apart from a magnex back box. thanks