just installed greedy turbo kit on 90 civic with d15b in it. only boosting 4 psi, but map code keeps coming on under hard accel. I know that I need some type of engine management unit, but the car I pulled the kit off never set that code. if you could please let me know any tips it would be appreciated.

 

Its called a Missing Link. Its a fancy check valve for the MAP sensor. Your kit apparently doesn't have that any more. Or I'm guessing the car you pulled it from actually used more than wishful thinking to manage boost.

I can tell you this, 6psi on a tiny turbo pushed 60% more whp out of my 8.53:1 D16 over 9.1:1 stock. Ignition timing thats okay (even conservative) for 0psi is way too much for even 4psi.

 

i have a missing link ,, 25$ shipped its 85 new