Here are the procedures out of my 94 Integra manual. Same principle, different car.

1. Do the ECM reset procedure.
2. Start the engine
3. Warm up engine to normal operating temperature
4. Do the road test
5. Is MIL on and does it indicate code 21?
NO: Intermittent failure. Check for loose and poor connections at VTEC solenoid valve and ECM.
YES: Continue on.
6. Turn ignition switch off.
7. Disconnect the 1P connector from the VTEC solenoid valve and check for continuity between 1P connector terminal and body ground.
8. Is there 14-30 ohms?
NO: Replace VTEC solenoid valve
YES: Continue on.
9. Connect test harness.
10. Check for continuity between 1P terminal and A4 terminal. Is there continuity?
NO: Repair open in the GRN/YEL wire between ECM (A4) and VTEC solenoid valve connector
YES: Continue on.
11. Check for continuity between 1P connector terminal (harness side) and body ground. Is there continuity?
YES: Repair short in the GRN/YEL wire between ECM (A4) and VTEC solenoid valve connector.
NO: Substitute a known good ECM and recheck. If symptom goes away, replace the original ECM.

Those wire colors and terminals are probably different but you have the basic idea of troubleshooting how a tech would do it.

I fear that code 23. I cracked my knock sensor and that code came up. New knock sensor: $180 at the dealer. :sad: