Tune-Up - Minor

Replace spark plugs and engine air filter, inspect belts and hoses, and check fluid levels to maintain optimal engine performance and fuel efficiency.

Warnings

Tools required

Parts

• Spark plugs (Iridium) × 4 — 90919-01253 or equivalent
• Engine air filter × 1 — 17801-0P051 or equivalent

Preparation

1. Park vehicle on level surface and engage parking brake
2. Allow engine to cool for at least 30 minutes
3. Gather all tools and parts before beginning
4. Verify new spark plugs match OEM specifications (pre-gapped to 0.043 inches)

Procedure

1. 1

   Remove engine cover
   Grasp the engine cover firmly and pull upward to disengage the rubber grommets from the mounting posts. The cover is held by friction-fit grommets only and requires no tools. Set cover aside in clean area.
2. 2

   Remove air intake duct
   Release the four clips securing the air box cover by lifting the wire tabs. Remove the air box cover and set aside. Lift out the old engine air filter and inspect the air box for debris. Clean if necessary with a shop towel.
   Torque spec

   Air Box Clips5 Nm (4 lb-ft)
3. 3

   Install new air filter
   Insert the new engine air filter into the air box, ensuring the rubber seal is properly seated around the perimeter. The filter is directional—arrows on the filter frame should point toward the engine. Reinstall the air box cover and secure all four clips.
   Torque spec

   Air Box Clips5 Nm (4 lb-ft)
4. 4

   Locate ignition coils
   Identify the four individual ignition coils on top of the engine. Each coil has an electrical connector and is held by a single 10mm bolt. Label or photograph coil positions if desired, though they are cylinder-specific.
5. 5

   Disconnect ignition coil connectors
   Press the locking tab on each ignition coil electrical connector and pull straight up to disconnect. Use gentle pressure—connectors should release easily. Keep connectors away from work area to prevent contamination.
6. 6

   Remove ignition coils
   Using a 10mm socket, remove the single bolt securing each ignition coil. Grasp the coil firmly and pull straight up with steady pressure to remove from spark plug well. Inspect coil boots for cracks or oil contamination. If boots are damaged, replace coils.
7. 7

   Remove old spark plugs
   Using a 14mm spark plug socket with extension, carefully remove each spark plug. Turn counterclockwise with steady pressure. Inspect removed plugs for abnormal wear, oil fouling, or electrode damage. Keep plugs in order for diagnosis if needed.
   ⚠If spark plug is difficult to turn, stop and apply penetrating oil. Do not force to prevent thread damage.
8. 8

   Inspect spark plug wells
   Use flashlight to inspect inside each spark plug well for oil, coolant, or debris. Wells should be clean and dry. If oil is present, valve cover gasket replacement is needed. Remove any debris with compressed air or shop vacuum before proceeding.
9. 9

   Install new spark plugs
   Verify new spark plugs are gapped to 0.043 inches (1.1mm). Apply small amount of anti-seize to threads if desired (not required for iridium plugs). Thread each plug by hand into cylinder head until finger-tight to prevent cross-threading. Torque to 18 lb-ft (25 Nm) using torque wrench.
   ⚠Start threading spark plugs by hand. Using a socket too early can cross-thread the aluminum cylinder head.
10. 10

    Reinstall ignition coils
    Apply thin layer of dielectric grease to inside of coil boots if available. Press each coil firmly into spark plug well until fully seated. Install and torque the 10mm mounting bolt for each coil. Reconnect electrical connectors until they click into place.
11. 11

    Inspect belts and hoses
    Visually inspect the serpentine belt for cracks, glazing, or fraying. Check belt tension by pressing midway between pulleys—deflection should be approximately 1/4 inch. Inspect all visible coolant and vacuum hoses for cracks, swelling, or leaks. Note any issues for future service.
12. 12

    Check fluid levels
    Check engine oil level on dipstick—should be between MIN and MAX marks. Check coolant level in overflow reservoir—should be at FULL mark when cold. Check brake fluid reservoir—should be at MAX line. Top off fluids as needed using specified Toyota fluids.
13. 13

    Reinstall engine cover
    Align engine cover rubber grommets with mounting posts on valve cover. Press down firmly on all corners until cover snaps into place. Ensure cover is secure and properly seated.

Reassembly

1. Ensure all electrical connectors are fully seated and locked
2. Verify no tools or parts are left in engine bay
3. Double-check that engine cover is properly installed

Verification

• Start engine and listen for smooth idle with no misfires or unusual noises
• Check for Check Engine Light—none should be present
• Allow engine to reach operating temperature and verify smooth acceleration
• Visually inspect for any fluid leaks around work area
• Test drive vehicle to confirm improved throttle response and smooth operation

Related trouble codes on this vehicle

Codes that commonly send this job to the bay — tap one for symptoms, causes, and diagnostic steps.

Chasing one of these codes and not sure which part is guilty? Ask a master mechanic about YOUR car →

More procedures for this vehicle