Remove the resonator (see page 11-448). Disconnect the VTEC solenoid valve 1P connector. Measure resistance between the VTEC solenoid valve connector terminal No. 1 and body ground. Resistance: 14-30 ohms If the resistance is within specifications, remove the VTEC solenoid valve assembly (A) from the cylinder head, and check the VTEC solenoid valve filter (B) for clogging. If there is clogging, replace the solenoid valve filter, the engine oil filter and the engine oil.

If the filter is not clogged, push the VTEC solenoid valve with your finger and check its movement. If the VTEC solenoid valve is normal, check the engine oil pressure.