d16y8 all stock except for turbo running 7lbs, skunk2 longtube intake,fuel pressure regulator ,cold air intake, 5zingen exhaust

car runs better when at 5lbs then 7. its set up for 7 but i ease the pedel to 5lbs and she goes better. also a/f guage drops to very left and light sits at lean low side after highway driving but works around town. i'm thinking o2 sensor what about you guys. and got electronic boost guage and mechanic said i need bigger injectors because of something wit fuel pressure regulator and injectors being held open at certain boost and thats it. I need some more info about this too . need the help and have about 1000 to shop wit and can do most things