Gas A = 96RON*
Gas B = 95RON*
*-gas company claimed

i notice that when i put Gas A in, i often hear backfiring whenever i decelerate or shift gear but when i use Gas B, i don't remember hearing it once. i haven't really test them out it's just what i've noticed.

could the higher octane be the cause or just bad tank of gas? by the way, i've tried getting Gas A from a different location and there's still backfire at times.

engine is b16 boosting at 7psi using the 'hack' as fuel management.

thanks.