My stagea which I've owned for about 48 hours is doing my head in! Bought it and drove home ( 80miles ) half a mile away from my home the car misfired and cut out. Would only start when cold. I've changed the afm and it now starts all the time but when it warms up its smokes ( black ) no power, and when you put your foot down and the boost reaches 0psi the fuel cuts out completely until you release the throttle. Changed afm and O2 sensor. Still no luck. Don't wanna have to get rid if the car already but I can't keep throwing money at it and I haven't even driven it properly yet! Please help!