1999 Subaru Impreza Owner's Manual - Page 266

5. Wipe the seating surface of the drain plug with a clean cloth and tighten it securely with a new sealing washer after the oil has completely drained out. Oil filter Sealing washer Drain plug OM-H0191 OM-H0192 6. Remove the oil filter with an oil filter wrench. 7. Before installing a new oil filter, apply a thin coat of engine oil to the seal. 8. Clean the rubber seal seating area of the lower crank case and install the oil filter by hand turning. Be careful not to twist or damage the seal. 9. Tighten it approximately two-thirds of a turn after the seal makes contact with underside of the crank case. CAUTION Never over tighten the oil filter because that can result in an oil leak. 10. Pour the specified amount of engine oil through the filler neck. Oil capacity: 4.2 US qt (4.0 liters, 3.5 Imp qt) 11. Start the engine and make sure that no oil leaks appear around the filter's rubber seal. 12. Run the engine until it reaches the normal operating temperature. Then stop the engine and wait a few minutes to allow the oil drain back. Check the oil level again and if necessary, add more engine oil. 10-10