The 2004 Honda Odyssey uses six spark plugs for its 3.5-liter V6 engine, and the factory plugs are typically iridium- or platinum-tipped units from NGK or Denso. Exact part numbers depend on market and the vehicle’s VIN, so check your owner's manual or a trusted parts database to confirm the correct replacement.
In more detail, the 2004 Odyssey employs a coil-on-plug ignition system, with one spark plug per cylinder. These plugs are chosen for longevity and reliable ignition performance, and Honda’s aftermarket replacements typically come in iridium- or platinum-tipped varieties. When shopping for replacements, most technicians use NGK or Denso parts that match the OEM specifications for this engine.
Spark plug types commonly used on the 2004 Odyssey
Before listing the options, note that the exact plug you need is VIN- and market-specific. The following types are commonly encountered for this engine:
- Iridium-tipped spark plugs (longer service life and strong ignition performance)
- Platinum-tipped spark plugs (solid performance with good longevity)
- OEM-equivalent NGK or Denso plugs (brands most often supplied as factory replacements)
The items above cover the standard options you would typically see when replacing spark plugs on a 2004 Odyssey.
How to determine the exact part for your vehicle
To ensure you buy the correct spark plugs, verify the exact part number using your vehicle’s VIN, the owner’s manual, or a trusted parts database. If in doubt, ask a parts counter with your VIN to confirm compatible NGK or Denso plugs and the correct gap and torque specs.
VIN-specific part numbers
Using the VIN ensures you get the precise OEM cross-reference and avoids mismatched plugs, especially important for regional market differences and production variations.
Replacement steps (overview)
If you choose to replace the plugs yourself, here are the general steps you would follow:
- Disconnect the negative battery terminal.
- Remove the engine cover (if present) and locate the six ignition coils and spark plugs.
- Unplug each coil connector, remove the coil and then the spark plug using the proper socket and extension.
- Set the new spark plug to the correct gap if required (many plugs come pre-gapped).
- Reinstall: torque to the manufacturer’s spec, reattach coils, and reconnect electrical connectors.
- Reconnect the battery and start the engine to verify proper operation.
Note: Torque and gap specifications vary by plug type and market. Always follow the OEM service manual for the 3.5L V6 (J35A) engine. If you are unsure, a professional mechanic can perform the replacement to exact specifications.
Maintenance and replacement guidance
On a 2004 Odyssey, iridium- or platinum-tipped plugs typically offer longer service life, with replacement often considered around 100,000 miles under normal driving conditions. Factors such as driving style, climate, and fuel quality can affect this interval. If you notice rough running, misfires, reduced fuel economy, or hard starting, it’s a good sign plugs may need inspection or replacement. Always use high-quality plugs and adhere to the manufacturer’s torque and gap specifications.
Summary
The 2004 Honda Odyssey uses six spark plugs in its 3.5-liter V6, with OEM replacements typically iridium- or platinum-tipped plugs from NGK or Denso. Confirm the exact part number for your VIN via the owner's manual or a reputable parts database, and follow the proper replacement procedure and torque specifications. If in doubt, consult a professional mechanic to ensure correct installation and performance.