2G Check engine light with misfire codes P0300, P0304, P1150 need help.

[talontsiboy24]

i have a 97 gsx automatic with moderate mods and about a month ago i replaced all the spark plugs with ngk bpr7es gapped at .026,new ngk me77 wires,new fuel filter new pcv,and i cleaned the maf sensor out with crc maf sensor cleaner...but before replacing all these things i kept getting a check engine light for P0300 and still with all the new stuff i keep getting these codes? i think i need a tune because the last one was like 3-4yrs ago... im running a walbro 255 without a afpr and i dont have a wideband...also my idle is jumpy it goes from 700-800 up and down never stays still when its warmed up.....

also noticed when im driving and the turbo is spooling and i let go of the gas pedal my idle drops to like 1000 and then goes down to like 100 and almost dies on me.....


i keep getting these 2 codes:

P0304 CYLINDER 4 MISFIRE
P0300 Random/Multiple Cylinder Misfire Detected
p1150 fuel pressure solenoid malfunction

 

[talontsiboy24]

Your car doesn't have a six bolt swap, does it?

no 7-bolt

 

[talontsiboy24]

should i put in new plugs and gap them at .028 and see what happens? because thats what they were last at but the tuner said .026 is better so i dunno...