last weekend i finished rebuilding the engine in my gti,i fired it up and its running and sounds good.the only problem i am having is that im getting a misfire on cylinder #6(p0306). i also get an occasional random/multiple cylinder misfire(p0300),only under heavy acceleration and until the enigne reaches about 4000rpm. i have replaced the spark plugs, the spark plug wires, and also tried switching the injectors,still without any luck.