Backfire problem

[crazyquik22023]

I have been running my car at 21psi daily for the last couple months and no problems with backfire. On my way home today i was trying to boost on the highway and my car stutters and backfires like crazy and my engine takes a shit. It boosts fine pulling from 2nd gear but when i tried to pull in 4th gear going about 60 mph it backfires horribly. same with 3rd gear around 40-50 and 5th gear around 60mph. some basic info on my car: E3B16G, walbro 255, 550's, Aeromotive -10AN FPR, full 3" exhaust, magnacore 8.5mm wires. Anyone input would be appreciated. thanks

 

[chadnum1]

question one, are you using a tuning device for the injectors? question two, have you done a boost leak test?

 

[crazyquik22023]

im using an safc for tuning sry i thought i put that and i haven't done a boost leak test but i dont think that would be it because it boost to 21psi normally in 2nd gear.