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.
Okinawa Prefecture (Japanese: æ²ç¸ç, Hepburn: Okinawa-ken, Okinawan: ã¦ããã¼ãã³ Uchinaa-chin) is the southernmost prefecture of Japan. It comprises hundreds of the Ryukyu Islands in a chain over 1,000 kilometres (620 mi) long. The Ryukyus extend southwest from Kyushu (the southwesternmost of Japan's four main islands) to Taiwan. The Okinawa Prefecture encompasses the southern two thirds of that chain. Naha, Okinawa's capital, is located in the southern part of Okinawa Island. Currently about half of the 53,000 U.S. troops deployed in Japan as part of the post-WWII security arrangement are based in Okinawa.