hi, i've got a seat ibiza cupra 1.8 turbo and im having some trouble with the boost, after spending nearly two grand trying to fix it, im on the verge of selling it, right the main problem is that the car is only boosting to 6psi when its been mapped to 23psi, and when im stationary an you give it a rev, it miss fires about 3000 rpm, and stinks of petty, these are some of the parts i have replace upto now, map, maf, n75, 4 coil packs, 4 spark plugs, brand new k03s turbo, lambar sensor, all the boost and vac pipes, could someone please help me, because im baffled