2005 Ford Focus L4-2.0L VIN N
Hello your vehicle has a timing chain, you do not have to replace it ever... It was designed to last the life of the vehicle, unless you have a water pump, or a timing pulley or even a timing tensioner go bad, that is when you would service the timing chain. I added what your vehicle needs at it's 90,000mile service below, hope this helps... (subytech1)
Brakes and Traction Control
Inspect brake pads, shoes, rotors, drums, brake lines & hoses, and parking brake system.
Inspect cooling system and hoses.
Fluid - A/T (Except 4F50N & 4F27E)
Inspect automatic transmission fluid level on all other vehicles, if equipped with dipstick.
Heat Shield, Exhaust
Steering and Suspension
Inspect steering linkage and suspension.
Vehicle (Multi-Point Inspection)
Perform Multi-Point Inspection (Recommended by Ford) Refer to Routine Service.
Inspect wheel ends for endplay and noise.
Cabin Air Filter
Replace cabin air filter, if equipped.
Fluid - A/T (4F50N & 4F27E Only)
Change automatic transmission/transaxle fluid on all vehicles
equipped with 4F50N & 4F27E. Inspect automatic transmission fluid
level on all other vehicles, if equipped with dipstick.
Oil Filter, Engine