alright i just finish swapping the jdm h22 into my 95 prelude si which has the h23. i use the h23 engine harness and fuel rail which is now perfect. the car's running, i wire vtec, which i believe the vtec wire is on the passenger side near the intake box, and it still throw code 21, which is vtec solenoid valve, i also have code 23 which is Knock sensor. the car also bogs sometimes from 1-3k rpm, what could be wrong.

 

oh yea, i'm also using a jdm p13 ecu.

 

You didn't connect KS nor vtec solenoid I suppose.
How many wires did you add to the existing harness?

 

i did connect the ks and vtec solenoid, i add two plugs only, which is the vtec solenoid and the vtec pressure switch which that should be it. since the h23 has knock sensor already.

 

Knock sensor may be bad, replace the current one with the one off the H23.

As for code 21, test your solenoid with a live wire from the battery while its running. Connect it to positve terminal while reving the engine.

Boggin is an EGR related issue. Unplug your EGR and see if it still bogs, if it doesnt you need an EGR

 

boggin at those RPMs sounds like an EGR issue. Unplug the EGR and see what happens

 

well i think it's because i rerouted the egr hose's wrong, since's it's a jdm intake manifold, it's a lil different from the us. there's also one more plug that's missing, and that's the one from the fuel pressure regulator. i'll check the egr.