snap crackle pop backfire
 

got a 1992 k1500, 7.4l 700r4, 5.7l ecm.. 454 tbi unit runs great, idles great, no vacuum leaks, but it pops and backfires at wot
running a heated o2 sensor, edelbrock shorty headers and downpipe 3" flowmaster exhaust has MSD blaster coil, 8mm wires, high end acdelco plugs, running a 45 series instead of 43. can't seem to get rid of it

lean air/fuel mixture at wot.

solution?

stronger fuel pump, bigger injectors. may have to have ecm checked to reprogrammed, possibly.

it still does it even with the 7.4l computer that came out of the 454ss pickup, and bigger injectors and stronger fuel pump don't sound like a solution to keep the engine from being modified. anything i can do without going to aftermarket stuff?