The knock sensor on a 1998 Honda Accord is designed to sense pre-ignition in the cylinders. Honda engines operate with high levels of ignition timing advance for more power and fuel economy. This leaves little margin for increased cylinder head temperatures because of fuel type, carbon deposits, cooling system abnormalities and load as well as other factors. A resounding “knocking” in the engine can identify pre-ignition. Pre-ignition is harmful because of the stress it places on internal components. The knock sensor signals the computer of this situation, which retards the spark until the knock is eliminated.
Disconnect the negative battery cable using a socket and ratchet.