P0302 on 2016-2017 Honda Odyssey: Cylinder 2 Misfire Causes & Fixes

What's Unique About the 2016-2017 Honda ODYSSEY

The 3.5L V6 engine (J35 series) in this generation of Odyssey uses a Variable Cylinder Management (VCM) system to improve fuel economy by deactivating cylinders during light-load cruising. A widely documented side effect of this system is that the piston rings on the deactivated cylinders (1-4) can allow oil to enter the combustion chamber. This oil burns and fouls the spark plugs, leading directly to misfire codes like P0302. This issue is so common that Honda has issued Technical Service Bulletins (like A25-061 and A26-001) and faced a class-action lawsuit for earlier model years with the same engine design. The 2016-2017 models exhibit the identical failure mode.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Symptoms You May Notice

• Rough or vibrating engine, especially at idle
• Hesitation or stumbling during acceleration
• Noticeable loss of power
• Solid or flashing Check Engine Light
• Activation of other warning lights like FCW (Forward Collision Warning) or LDW (Lane Departure Warning) as the misfire can affect these systems.
• Shuddering when the 'ECO' light turns on, indicating VCM engagement.
• Noticeable oil consumption between oil changes.

Most Likely Causes

1. Oil-Fouled Spark Plug in Cylinder 2 🔴 High Probability This is the primary symptom of the VCM-related oil consumption issue. Oil seeps past the piston rings on deactivated cylinders, creating carbon deposits on the spark plug, which prevents it from firing properly. This is explicitly mentioned in Honda TSBs #A26-001 and #A25-061.
   How to confirm: Remove the spark plug from cylinder 2. Cylinder 2 is the middle cylinder on the rear bank, closer to the firewall. It will likely be coated in wet, black, oily deposits. Compare it to a plug from a non-VCM cylinder (e.g., cylinder 5 or 6 on the front bank), which should be much cleaner.
   Typical fix: Replace the fouled spark plug. It is highly recommended to replace all six spark plugs at the same time using OEM-spec NGK or Denso Iridium plugs. This is a temporary fix if the root cause is not addressed.
   Est. part cost: $15-$30 per plug
2. Worn or Sticking Piston Rings 🔴 High Probability This is the root cause of the oil-fouled spark plugs. The VCM system's operation can cause the piston rings on cylinders 1-4 to align or stick, allowing oil to bypass them. An owner complaint for a 2016 Odyssey specifically refers to this as the 'piston ring problem' identified by a Honda service center. TSB A25-061 confirms this issue for 2013-2017 models.
   How to confirm: A definitive diagnosis requires a cylinder leak-down or compression test. Consistent oil fouling of the spark plug in cylinder 2, 3, or 4 is a strong indicator. The vehicle will also show signs of excessive oil consumption (e.g., needing 1 quart every 1000-1500 miles).
   Typical fix: This is a major engine repair that involves disassembling the engine to clean the pistons and replace the piston rings on the affected cylinders (typically 1-4). Some owners install an aftermarket VCM-disabling device ('VCM Muzzler' or 'VCMTuner') to prevent the issue from recurring by keeping the engine in 6-cylinder mode.
   Est. part cost: $50-$150 for a piston ring set.
3. Faulty Ignition Coil on Cylinder 2 🟡 Medium Probability Ignition coils are a common wear item on any vehicle. While not specific to the VCM issue, a coil can fail and cause a single-cylinder misfire. It is often incorrectly blamed when the true cause is an oil-fouled plug.
   How to confirm: Swap the ignition coil from cylinder 2 with another cylinder (e.g., cylinder 5, which is on the front bank and easier to access). Clear the codes and drive the vehicle. If the misfire code changes to P0305, the ignition coil is faulty. Note: A faulty coil may also show higher internal resistance compared to other coils when tested with a multimeter.
   Typical fix: Replace the faulty ignition coil.
   Est. part cost: $50-$100
4. Clogged or Faulty Fuel Injector ⚪ Low Probability
   How to confirm: If spark (plug and coil) and compression are good, the fuel injector is the next item to check. This usually requires a professional diagnosis involving an injector balance test.
   Typical fix: Replace the faulty fuel injector.
   Est. part cost: $70-$150

Rare But Worth Checking

• Valve Adjustment Needed: Incorrect valve lash (clearance) can cause compression issues and lead to misfires. The J35 engine requires periodic valve adjustments, which are sometimes overlooked. One forum user with a 2013 Odyssey and multiple misfire codes (P0302, P0303, P0304) found that a valve adjustment fixed the issue after new plugs only provided a temporary solution.

Diagnosis Steps

1. Read the trouble codes with an OBD-II scanner to confirm P0302 and check for any other codes, especially P0301, P0303, or P0304.
2. Note if the Check Engine Light is flashing, which indicates a severe misfire that can damage the catalytic converter. Do not drive the vehicle if it is flashing.
3. Locate cylinder 2. On the J35 engine, the cylinders closest to the radiator are 4-5-6 (Bank 2). The cylinders closest to the firewall/windshield are 1-2-3 (Bank 1). Cylinder 2 is the middle cylinder on the rear bank.
4. Swap the ignition coil from cylinder 2 with an easier-to-access cylinder (e.g., cylinder 5). Clear the codes and see if the misfire moves to P0305. If it does, the coil is bad.
5. If the misfire remains on cylinder 2, remove the spark plug. This may require a swivel socket and extensions for the rear bank. Inspect it for signs of heavy, black, oily deposits, which confirms oil fouling.
6. If the plug is fouled, replace all six spark plugs with OEM-spec Iridium plugs (NGK or Denso). This is often a temporary fix, as the issue is likely to return if the underlying oil consumption problem is not addressed.
7. To address the root cause, consider installing a VCM disabling device ('VCM Muzzler' or similar). Many owners report this stops the oil consumption and prevents future plug fouling.
🎬 Watch this step-by-step VCM muzzler installation for your Odyssey.
8. If the problem persists after new plugs and coils, a compression test and/or leak-down test is necessary to check for internal engine problems, such as the known piston ring issue.
9. If all ignition and compression tests pass, the fuel injector for cylinder 2 may be at fault, which may require professional diagnosis.

Parts You'll Likely Need

• Spark Plug (OEM #12290-R71-L01) — This is the most common failure point due to oil fouling from the VCM-related piston ring issue. Using the correct OEM Iridium plug is critical.
  Trusted brands: NGK (DILZKR7A11G), Denso
  OEM price range: $20-$30
  Aftermarket price range: $15-$25
• Ignition Coil (OEM #30520-R70-S01) — A standard wear item that can cause a single-cylinder misfire. It's a common diagnostic step to swap and replace.
  Trusted brands: NGK, Denso, Hitachi
  OEM price range: $90-$125
  Aftermarket price range: $50-$100
• Piston Ring Set (OEM #13011-R70-A12) — The root cause of VCM-related oil consumption. This part number is for a single piston set. The repair typically involves replacing the rings on cylinders 1-4. This is a major repair and often only performed under warranty or as a last resort.
  Trusted brands: Honda (OEM)
  OEM price range: $45-$65 per cylinder
  Aftermarket price range: N/A

Related Codes That Often Appear With This One

• P0300 — Indicates a random misfire. This can appear if the misfire on cylinder 2 is intermittent or if other cylinders are beginning to misfire as well due to the same VCM issue.
• P0301, P0303, P0304 — These codes indicate misfires in cylinders 1, 3, and 4. They often appear with P0302 because the VCM system can cause oil fouling across the entire bank of cylinders it deactivates (cylinders 1-4).
• P3400, P3497 — These codes are related to the VCM system itself (rocker arm oil pressure switches). They can appear in conjunction with the oil consumption and misfire issues and were the subject of TSB 11-033, which involved a software update.
• P0420, P0430 — Catalyst efficiency codes for Bank 1 or Bank 2. A chronic misfire allows unburnt fuel to enter the exhaust, which can overheat and destroy the catalytic converter over time, leading to these codes and a very expensive repair.

Technical Service Bulletins (TSBs) & Recalls

• A26-001: Mentions oil sludge causing carbon fouling on spark plugs, leading to DTCs P0301-P0304.
• A25-061: Specifically for 2013-2017 Odyssey, extends warranty coverage for misfires on cylinders 1-4 due to piston rings deteriorating from wear and sludge. Outlines repair involving piston cleaning, ring replacement, and a PCM software update.
• A13-080: Details the class-action settlement and warranty extension for 2008-2013 models with the same P0301-P0304 misfire issue, explaining that piston rings may rotate and align, causing spark plug fouling.
• 11-033: Addresses engine oil consumption and codes P3400/P3497 on earlier models, recommending a PGM-FI software update to alter VCM engagement behavior.

Platform-Specific Known Issues

• Piston Ring / Oil Consumption Issue: As documented in TSBs like #A25-061, oil sludge and carbon fouling of spark plugs are a known problem leading to P0301-P0304 codes on 2013-2017 models. An owner of a 2016 Odyssey reported this was called the 'piston ring problem' by their Honda service center (NHTSA ODI #11321682). This is a direct result of the VCM system's operation.
• Warranty Extension for Earlier Models: Honda issued a warranty extension (TSB 13-080) for 8 years/unlimited miles to cover this exact piston ring issue on 2008-2013 models. While 2016-2017 models were not officially included in that specific settlement, they use a very similar engine design and exhibit the same failure mode, as acknowledged in later TSBs.
• Effectiveness of VCM Disablers: A significant portion of the owner community on forums like Odyclub.com and Reddit advocate for installing a 'VCM Muzzler' or similar device. Long-term reviews show that these devices, which prevent the engine from switching out of 6-cylinder mode, can successfully stop or drastically reduce oil consumption and prevent spark plug fouling from recurring.

Mechanic-Grade Diagnostic Values

• Ignition Coil Resistance (3-pin type) — expected: Approx. 1725-1730 Ω between the first two pins on a known-good coil.. Failure: A significantly higher reading (e.g., 1835 Ω) can indicate a failing coil, even if it hasn't failed completely.
• BARO (Barometric Pressure) Sensor Voltage — expected: Approximately 2.88 V at sea level. This sensor is inside the PCM.. Failure: Incorrect voltage can affect air-fuel calculations. The voltage changes with altitude.

Hidden / Shadow Codes Worth Checking

• On-Board Snapshot / Freeze Data: The Honda Diagnostic System (HDS) can capture and display 'On-Board Snapshot' or 'Freeze Data', which is a detailed record of engine parameters (like engine speed, coolant temp, etc.) at the exact moment a misfire or other DTC was first logged. This provides much more context than the code alone. (see via Honda HDS (dealer/specialist scanner).)
• Mode $06 Misfire Data (e.g., CYL CRANK SPEED #2): While not a 'hidden code', the HDS provides access to live data parameters like 'CYL CRANK SPEED #2'. The PCM uses the change in crank speed after a cylinder's combustion event to determine if a misfire occurred. Monitoring this value directly can confirm which cylinder is misfiring in real-time. (see via Honda HDS or advanced OBD-II scanner with Mode $06 support.)

Scan Tool Commands That Help

• Honda HDS (Honda Diagnostic System): CKP Pattern Clear — This command erases the learned crankshaft position sensor pattern from the PCM's memory. It is specifically recommended to be used after a repair for a misfire or after replacing the CKP sensor itself to force the system to relearn the new pattern.
• Honda HDS (Honda Diagnostic System): ECM/PCM Reset — This is a more comprehensive reset than a generic code clear. It erases all stored DTCs, freeze data, and learned fuel trims, but does not erase the CKP pattern. This should be used after replacing components to force the system to relearn operating parameters.

Wiring & Ground Locations

• G101 — Located on the front of the right cylinder head (Bank 1, the rear bank).. This is a primary ground point for the PCM and various engine sensors. A poor connection here can cause erratic sensor readings and misfire-related issues.
• G201 — Located on the bottom left side of the engine compartment, often near or under the battery tray.. This is another critical engine compartment ground. Corrosion or a loose connection at G201 can lead to various electrical problems, including issues with the ignition system.

Real Owner Repair Stories

• Reddit user on r/HondaOdyssey (2016 Honda Odyssey) — Check engine light with code P0302 for cylinder misfire.
  ❌ Tried (didn't work) The user was facing a potential dealer repair under an extended warranty for the piston ring issue.
  ✅ What actually fixed it The community strongly recommended installing a 'VCM Muzzler' to disable the VCM system as the permanent solution to prevent the oil consumption and spark plug fouling that causes the misfire.
• YouTube channel '2CarPros' (Honda Odyssey (model year not specified, but J35 engine)) — Misfire on Cylinder 3 (P0303, but same diagnostic principle as P0302).
  ❌ Tried (didn't work) Swapping the ignition coil from the misfiring cylinder to another cylinder did NOT cause the misfire code to move.
  ✅ What actually fixed it The spark plug in the misfiring cylinder was found to be worn out. However, resistance testing also showed the original ignition coil on that cylinder had a higher resistance (1835 ohms) compared to the others (around 1730 ohms). The final fix was replacing all spark plugs AND the suspect ignition coil, which resolved the misfire.

OEM Part Supersession History

• 30520-R70-A01 → 30520-R70-S01 — Part revision by manufacturer.
  Heads up: The new part number is a direct replacement for the old one.
• 13011-R70-A01 → 13011-R70-A02 — Part revision by manufacturer. Note: This part number primarily fits older (pre-2011) J35 engines.
  Heads up: While a valid part, 13011-R70-A12 is the more appropriate number for the 2016-2017 Odyssey.
• 13011-RV0-A01, 13011-5G0-A01, 13011-5G0-A02 → 13011-R70-A12 — Consolidation and revision of part numbers for the piston ring set (for one piston).
  Heads up: This is the correct OEM piston ring set for the 2011-2017 Honda Odyssey.

Model Year Variations Within This Range

• 2016-2017: There are no significant mechanical or engine-related differences between the 2016 and 2017 Honda Odyssey models. Both use the same J35Z8 engine with the same specifications and are subject to the same VCM-related issues.