This is an in tank fuel pump. The correct tool for removing the fuel pump lock ring is # T10202. The fuel pump supplies fuel pressure to the injection system and is an essential component in almost all automotive applications. In modern applications this pump is usually electric and expected to deliver fuel at high pressure to meet the performance and emissions demands of todays motors. The fuel pump is normally located inside the fuel tank and be accessed in some cases from above without lowering or removing the tank. Loss of power under load and no start situations are all possible indications of a malfunctioning fuel pump, especially if the vehicle has 100,000 miles or more and is operating on the original fuel pump. It is recommended that the fuel strainer where applicable be replaced at the same time. It is also recommended that the car’s main fuel filter be replaced at regular service intervals of roughly 30-50k miles.