speakers;2ways;component;

recently i overhauled my 4g93t gsr rs. I replace a few thing
1. rebore from 81.0 to 81.5,
2. my standard piston ratio is 9.1:1 for the new piston is 8.9:1.
3. I also replace the head gasket from o.8 to 1.5mm.
4. fuel injector from 390 to 450cc
5. throttle body up grade to evo 111
6. fit an afc
my problem is when i put the afc little bit lean my exhaust manifold will red hot but if i put little bit rich it will be sluggish

need some help
i have been using this...