Sets code p0300, fowling plugs(fuel) no other codes, other sensers look normal on scan tool. MAF senser? reads approx 3.4 grains @ idle around 12@ 2000 rpms. This seems a bit low, but I would expect a lean condition from that though. Can't accelorate very hard, misses very bad . Same after cleaning plugs. Anyone have any ideas ? 60000 miles on vehicle