put a superchip on my dads truck, 01 5spd 3500. on tow it runs okay and no clatter. on tow/per it runs better but start to notice clatter or rattleing sound. and on performance the noise is even more noticable at about 1200-1400 rpm. is this just the added timing from the chip or is this a bad sound from the injectors that needs to be adressed. truck has been stock as far as chips or programmers since new and has bout 90,000 on it now. thanks for any help.