Ok car is 96 with b16 P30, Dc header, Aem V2, MSD 8mm plugs. I just changed my spark NGK Iridium 6 but it hasnt been 30000 miles and torque 1/2 to 2/3 and now my gas just drops when steadying driving 70 on the high way and when changing gears does it to. Looking at the spark plug its grey, white on top and build up carb on the ring. When at idle it doesnt drop as much. The distributor is Mr Gasket clear so when looking at it spark at night i see a slight difference in the spark 3 cyl sparking really bright the other just a tiny bit you see spark but not dramatically . You think it could be off timing. Could it also casue me to run rich if its off timing??????? Anyone help me. Thanks

 

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Maybe just a simple tune up, can improve gas mileage.
Wires, plugs, rotor, cap, air filter.