you have to make sure you get the dohc vtec fluid also, otherwise it wont work.

 

ok these are the exact codes

21 VTEC spool solenoid valve
23 Knock sensor

 

that sounds better.

 

if your knock sensor is not working i dont think it will allow vtec to engage since the ecu will have no way of detecting detonation. code 21 is the pressure switch code. is it wired right? maybe try running a wire from the harness to a ground somehwer to fool the ecu?

 

wierd i didnt know that ....i have a jdm b16a on a usdm p28 and when i dropped in the swap and took it for a test drive vtec worked fine for me.

maybe bcuz its b16a already has the pressure switch?