hey guys, my 86 has been having some issues lately...got cel that pops up when in closed loop, but doesn't store any codes, and also getting completely crap mileage. i replaced o2 with no effect. I managed to pull a code a while back and it gave me code 3...no signal from igniter or coil 4 times in succession, and also knock sensor code. is it possible that the truck will still run with the igniter being bad and could this be the cause of the bad mileage? like its just generating a weak spark? Ima get ohm meter and check the coil but its pretty new. im getting about 10 mpg and wana get this thing fixed asap. any help would be appreciated.

 

also worth mentioning plugs cap rotor wires were all replaced not even couple thousand miles ago.

 

anyone?