i have a d16y8 with a t-25, 450's and a smc dual. i am having problem with it mis firing. had 2 step colder ngk plugs, switched to 1 step colder and runs worse. before and after it's been throwing code 71(cylinder no. 1 misfire);code 72(cylinder no. 2 misfire); code 73 (cylinder no.3 misfire); and code 74 (cylinder no. 4 missfire). my setting on the smc dual are idle-35 starting at 2000 rpm -40 down to -35 at 7000 rpm. any one know what the hell is going on??

 

what did you use as the resistor for the 450's? if you used the 10w 10ohm radio shack resistors they tend to arc unless you cover the electrodes good. and if your not running a resistor box that is your problem