Diesel particulate filters (DPF) require routine cleaning to remove ash that builds up over time. Most vehicles using a DPF system will have an on-board filter service monitor to indicate the filter condition and guide your filter cleaning schedule.
In ancient times the islands formed an independent kingdom. Chinese and Japanese sovereignty were successively forced on the archipelago from the 14th to the 19th century, and in 1879 the Ryukyus became an integral part of Japan. After the defeat of Japan (1945) in World War II, the United States took control of the islands.
On August 12, 1898, the government of the Republic transferred sovereignty to the United States. Hawaii became a territory of the United States in 1900. Toward the end of the 19th cent., agitation for constitutional reform in Hawaii led to the overthrow (1893) of Queen Liliuokalani, who had ruled since 1891. A provisional government was established and John L. Stevens, the U.S. minister to Hawaii, proclaimed the country a U.S. protectorate.