I have just put a d16 head non-vtec on a d15 block, added mpfi to the car, i have done all the necesary wiring and mods that i needed to. I went to start and got a code 4 from the si distributor. I know this is a noob question but i am at my wits end, what is the best course of action to do from here? I have all the grounds and wiring conections done.

 

check the 2 wires that you added to the dizzy, see if you put them on backwards.
if not and your wiring is right - change the dizzy...

 

^ x2,and VERY common mistake to have them bassackwards due to different writeups online... (some view back of ecu plugz,some the front making wiring well-backwards) Try de-pinning @ dizzy and swap them (or @ ecu if easier for ya) Hope that made sense

 

Check wiring connections, if they're not tight, the ECU will notice the difference in voltage and give you a code. Don't buy parts that you do not need.

 

i have added four wires total to the ecu harness which pins do i need to try and switch, larger pins and smaller pins.