Ever since I had my superchip fitted my car make a knocking niose from the engine when I start it up sometimes, after I rev the engine it goes away??. also the car belts out a hell of alota white smoke until the engine gets warm. It this normal? are the two related? Ive also got a hillpower iK and a magnex cat back system. The car runs better than before. So performance doesnt seem to be affected. Its just worrying when it makes the deep knocking noise.