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Autopapyrus · Toyota Yaris 1.5 Hybrid (2022)
https://autopapyrus.com/guides/toyota/yaris/spark-plug-replacement/
Compiled automatically from service literature and owner experience. Specs are for the typical configuration — check them against your exact car before you start.

Toyota Yaris 1.5 Hybrid (2022): Spark Plug Replacement

Spark plugs on a hybrid Yaris work under special conditions: the engine starts and stops frequently, so it's best not to stretch the replacement interval. It's usually about 90,000-100,000 km, and sooner with mostly city driving. The coils sit directly on the plugs (one per cylinder), and you get access to them after removing the decorative engine cover.

Difficulty: Medium Time: 45-90 minutes Steps: 14 Tools: Spark plug socket with rubber retainer (long, usually 16 mm for iridium plugs, sized to match your plug), universal-joint extension, low-range torque wrench, 10 mm socket for the coil and cover fasteners, pliers or a screwdriver for connector locks, compressed air or a vacuum cleaner, thin dielectric grease for the rubber coil boots.

Part

  • 🔩 Set of iridium spark plugs, one per engine cylinder (NGK or Denso, in the version approved by Toyota for the hybrid model). Look up the part number by VIN so it matches the original plug for your specific engine. Plugs from the previous-generation 1NZ-FXE (4-cylinder) may not fit a car of this generation
There's a full repair manual for this car Every system, wiring diagrams and torque specs — not just this job. Haynes and 7 more. See manuals →

Step by step

14 steps
  1. Park the car on level ground and set the parking brake. Turn the system off with the Power button so the READY indicator goes out, then remove the key fob or move it away from the car. Wait for the engine to cool completely, ideally 1-2 hours. On a hybrid the engine can start by itself, so never work while READY is on.
  2. Open the hood. Disconnect the negative terminal of the 12-volt battery (it's in the trunk or under the hood, depending on trim). Do not touch the orange high-voltage cables and connectors; you don't need them for this job.
  3. Remove the decorative engine cover. It is held by nuts or screws (often a 10 mm socket) or by clips.
  4. Inspect the area around the coils and blow off dirt with compressed air so it doesn't fall into the spark plug wells.
  5. Disconnect the coil electrical connectors. Press the lock tab; don't pull on the wires. Work on one coil at a time so you don't mix up the connectors.
  6. Remove the coil mounting bolts (usually one 10 mm bolt per coil). Pull the coil straight up, rocking it slightly. Inspect the rubber boot: cracks or traces of oil are a reason to replace the coil.
  7. Check the spark plug well. If there are traces of oil, check the valve cover seals. Blow out the well with air.
  8. Remove the spark plug with a long socket with a retainer and an extension. Keep the wrench exactly in line with the plug, without tilting.
  9. Evaluate the condition of the old plug. Light gray deposits mean normal operation. Dry black deposits mean a rich mixture. An oily film means problems with the valve stem seals or piston rings. White deposits mean a lean mixture. If the plug from one cylinder looks abnormal, diagnose that cylinder separately.
  10. Check the gap on the new plugs. It is listed in the plug specifications or the maintenance schedule. Iridium plugs come pre-gapped, so do not bend the electrode. Do not lubricate the threads unless the manufacturer requires it.
  11. Thread the new plug in by hand for several turns so you don't strip the threads in the aluminum head. Then tighten it with a torque wrench. For plugs with a tapered or flat seat, the torque is usually 18-25 N·m (13-18 lb-ft); take the exact value from the maintenance schedule or the specific plug's packaging. Tightening by feel is dangerous for the head threads.
  12. Apply a thin layer of silicone grease to the inside of the coil boot. Seat the coil on the plug until it clicks, install the bolt (the torque is low, about 5-10 N·m (44-89 lb-in)), and connect the connector.
  13. Repeat steps 5-12 for the remaining cylinders.
  14. Install the engine cover. Reconnect the negative battery terminal. Turn the system on and let the engine start and run. Listen for smooth running and check that there are no warning lights on the instrument panel. After the battery is disconnected, the clock and trip computer settings may be reset.

Common mistakes and warnings

  • Do not work on the orange high-voltage components and cables. If you are not confident working around a hybrid system, or you can't determine the exact type and size of the plugs, have a repair shop do the job. Do not use impact wrenches, and do not thread plugs in crooked: threads in an aluminum head strip easily, and the repair will be very expensive.