I used to have both codes 21 and 23 now I redid some of the wiring and no longer have the code 23. The only thing left is code 21. I am not sure how I could solve this problem, the car does have MSD ignition I dont know if that could be the problem. I Bought the car with the motor already installed, so it makes it more difficult for me to diagnose the probleme. The car did not pass emissions but that is when both codes 21 and 23 were on, could the codes im throwing cause higher emmsions. As always thank you guys for all of your help.

 

code 21 VTEC spool solenoid valve. Check wiring and report back.

 

which motor and ecu are you running?? pics would help also

 

as the title states its a b16 obd0

 

checked the wiring, some wires seem like they could be off but none of them have to do with VTEC