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.
ALASKA was a Russian colony from 1744 until the USA bought it in 1867 for $7,200,000. It was made a state in 1959. Hawaii was a kingdom until 1893 and became a republic in 1894. It then ceded itself to the USA in 1898 and became a state in 1959. IMMEDIATELY before Hawaii achieved statehood in 1959, it was a Territory of the US. However, it had been a sovereign constitutional monarchy until 1893, when the last Queen, Lili'uokalani, was deposed by a group of American sugar planters and missionaries, with the support of the US marines.