94 GSR gave a check engine light 21. Light comes on during hard throttle. Thought it was an oil shortage issue. Checked on board, and some have had this problem before. One user changed the VTEC solenoid. Others suggested it could be the wiring, namely pin A8. The check engine light codes for 21 show that it is a VTEC spool solenoid valve. Anyone have this CEL code and what did you do to fix the problem?