Just brought another s2 of a mate,but has a problem,it dont seem to boost properly and makes a strange whineing noise not the usaul loud sucking noise?and seems as if theres some sort of faint missfire there?Also now and then it will thro out big puffs of white smoke,did it just sitting there ticking over and also as i stoped at a junction?

Any help asap with be greatfull cheers