Alright so i have tried lots of things to fix my problems so i thought i would ask on here. I have a 93 si that i swapped a h22a1 into. it is bored and sleeved also has a skunk 2 pro series intake with some bolt ons using the h23 wiring harness. anyways i have changed the knock sensor and it did not help. i then started throwing code 20 when i replaced it.when it is cold it starts to cut out like a hiccup. then when its warmed up it will do it ramdonly until it throws a check engine light then it stops. can anyone help. i heard that if you start to add lots of bolt ons it will throw the codes until you chip the ecu. any advice will help thanks

 

I also wanted to know if im correct but is the black box by the ecu the pgm fi relay?