P0302 on 2006-2011 Hyundai Azera 3.8L: Cylinder 2 Misfire Causes and Fixes

What's Unique About the 2006-2011 Hyundai Azera

The 2006-2011 Azera uses the reliable, port-injected (MPI) version of the Lambda 3.8L V6 (engine code G6DA), which avoids the carbon buildup issues on intake valves seen in later GDI (Gasoline Direct Injection) engines. For this vehicle, a P0302 code is almost always a straightforward ignition or spark issue. The key is knowing the cylinder layout: the Azera's engine is mounted transversely (sideways), so Cylinder 2 is on the front bank of cylinders (Bank 2), closest to the radiator. This makes it relatively easy to access for diagnosis and repair compared to the rear cylinders (Bank 1) which are tucked against the firewall.

Symptoms You May Notice

• Rough idle or shaking at a stop
• Hesitation or stumbling during acceleration
• Noticeable loss of engine power
• Flashing or solid Check Engine Light
• Decreased fuel economy
• Smell of unburnt fuel from the exhaust
• Engine is hard to start

Most Likely Causes

1. Faulty Ignition Coil 🔴 High Probability → Shop Ignition Coil Ignition coils are a common wear item on most modern vehicles, including the Lambda V6. Constant heat cycles and engine vibration eventually cause the internal windings to break down, leading to a weak or no-spark condition.
   How to confirm: Swap the ignition coil from cylinder 2 with the one from cylinder 4 (the middle cylinder on the same front bank). Clear the codes using an OBD-II scanner. Start the engine and let it idle or drive for a few minutes. If the misfire code changes to P0304, the coil is definitively bad.
   Typical fix: Replace the faulty ignition coil. It is often recommended to replace all three coils on the same bank (Bank 2) at the same time, as they have experienced the same wear. Given the ease of access, many owners do this preventatively.
   Est. part cost: $40-$75
2. Worn or Fouled Spark Plug 🟡 Medium Probability → Shop Spark Plug Spark plugs have a finite service life (typically recommended for replacement around 100,000 miles) and must be replaced at regular intervals. An overdue plug, or one fouled by oil from a leaking valve cover gasket, can easily cause a misfire.
   How to confirm: After confirming the ignition coil is good, remove the spark plug from cylinder 2. Inspect it for a worn or rounded electrode, cracks in the porcelain, or heavy deposits of carbon or oil. You can also swap it with the plug from cylinder 4. If the code changes to P0304, the spark plug is the issue.
   Typical fix: Replace the spark plug. It is best practice to replace all six spark plugs at the same time if they are near the end of their service life. The rear plugs are much more difficult to access, 🎬 See this walkthrough for replacing Azera spark plugs and coils. so it makes sense to do them all at once.
   Est. part cost: $10-$25 per plug
3. Clogged or Faulty Fuel Injector ⚪ Low Probability → Shop Fuel Injector While less common than ignition issues on this MPI engine, fuel injectors can become clogged with deposits over time, preventing them from delivering the correct amount of fuel. In some Hyundai vehicles, an owner reported in NHTSA ODI #11606012 that an injector failed open, which flooded the cylinder with fuel and resulted in gas in the oil.
   How to confirm: If the ignition coil and spark plug are good, the injector is the next likely cause. A more advanced DIY test involves using a mechanic's stethoscope or a long screwdriver to listen to the injector; you should hear a consistent, rapid clicking sound. If it's silent or irregular compared to other injectors, it may be faulty. A professional can perform a fuel injector balance test for definitive diagnosis.
   Typical fix: Replace the fuel injector for cylinder 2.
   Est. part cost: $70-$150

Rare But Worth Checking

• Leaking Valve Cover Gasket: → Shop Engine Valve Cover The valve cover gasket and the spark plug tube seals can become brittle and leak oil directly into the spark plug well. 🎬 Watch: How to replace a leaking Azera valve cover gasket. This oil can short out the ignition coil and foul the spark plug, causing a misfire. If you find oil on the spark plug boot or in the well when you remove the coil, this is your likely root cause. There is a related TSB (12-EM-004) concerning the proper procedure for sealing the cylinder head cover.
• Intake Manifold Gasket Leak: → Shop Engine Intake Manifold A vacuum leak near the intake runner for cylinder 2 can lean out the air/fuel mixture and cause a misfire. A mechanic can test for this with a smoke machine.
• Low Engine Compression: This indicates a more serious mechanical engine problem, such as a worn piston ring, a burnt valve, or a problem with the cylinder head gasket. A compression test is needed to diagnose this. NHTSA ODI #11221514 describes a situation where a vehicle suddenly stuttered and stalled at low RPM, and the dealership found cylinder 2 had little to no compression.
• Timing and Valvetrain Issues: Though rare for a single cylinder, internal mechanical failures can occur. NHTSA ODI #11606626 notes a case where codes P0300, P0302, P0304, and P0306 were present, and the technician recommended replacing the intake camshaft, CVVT, and timing chain tensioner.

Diagnosis Steps

1. Confirm the code is P0302 using an OBD-II scanner.
2. Identify the cylinder banks. Bank 1 (cylinders 1, 3, 5) is against the firewall. Bank 2 (cylinders 2, 4, 6) is at the front of the engine bay, by the radiator.
3. Locate cylinder 2. It is the first cylinder on your left when facing the front of the engine (driver's side).
4. Perform the 'Ignition Coil Swap Test'. 🎬 Watch: How to diagnose a P0302 misfire and swap coils. Unplug and remove the ignition coil from cylinder 2 and cylinder 4 (the middle one on the front bank). Swap their positions.
5. Clear the trouble codes with the scanner, start the engine, and let it run for a minute. Re-scan for codes.
6. If the code is now P0304 ('Cylinder 4 Misfire Detected'), the ignition coil you moved from cylinder 2 is faulty. Replace it.
7. If the code remains P0302, the coil is likely good. Remove the coil again and check the spark plug well for any signs of oil. If oil is present, the valve cover gasket/tube seals are leaking and must be replaced.
8. If no oil is present, proceed to check the spark plug. Swap the spark plugs between cylinders 2 and 4 and repeat the test.
9. If the code moves to P0304 after swapping plugs, the spark plug is bad. Replace it (and preferably all six if they are old).
10. If the code still remains P0302 after swapping both the coil and the plug, the issue is likely a fuel injector or a mechanical problem, which may require professional diagnosis.

Parts You'll Likely Need

• Ignition Coil (OEM #27301-3C000 (supersedes 27301-3C010)) — This is the most frequent failure point for a single-cylinder misfire on this engine. The part number is often listed without a hyphen as 273013C000.
  Trusted brands: Hyundai (OEM), Denso, NGK, Delphi, Beck/Arnley
  OEM price range: $75-$110
  Aftermarket price range: $40-$75
• Spark Plugs (OEM #27410-23700 (Vendor: NGK, #IFR5G-11)) — A worn or fouled spark plug is the second most common cause. They are a routine maintenance item. This part number may also supersede 27410-3C000.
  Trusted brands: NGK (OEM supplier), Denso, Bosch
  OEM price range: $20-$30 per plug
  Aftermarket price range: $10-$25 per plug

Related Codes That Often Appear With This One

• P0300 — If the misfire is intermittent or severe, the computer may also log a P0300 'Random Misfire' code alongside the specific cylinder code.
• P0304, P0306 — If multiple misfire codes appear for the same bank (2, 4, and 6 are all on the front bank), it could point to a shared problem like a bad ground connection, a vacuum leak affecting that entire bank, or a leaking valve cover gasket on that side.

Technical Service Bulletins (TSBs) & Recalls

• TSB 12-EM-004: Provides the correct procedure for sealing the cylinder head cover after removal, which is critical when replacing a leaking valve cover gasket that may have caused the misfire.
• TSB 10-EM-006: Referenced in a YouTube video concerning timing cover removal, which can be related to oil leaks in the front of the engine.

Platform-Specific Known Issues

• Oil Leaks into Spark Plug Wells: → Shop Spark Plug A common issue on higher-mileage Lambda V6 engines is the degradation of the valve cover gaskets and spark plug tube seals. This allows engine oil to pool in the spark plug wells, which can saturate and destroy the ignition coil and foul the spark plug, directly causing a misfire code like P0302. TSB 12-EM-004 provides specific instructions for applying RTV sealant when replacing these gaskets to ensure a proper seal.
• Excessive Oil Consumption: Some Hyundai owners have reported that excessive oil consumption, potentially due to ring wear or sticking rings, has contributed to engine codes P0300, P0302, and P0303 (NHTSA ODI #11669597).

Mechanic-Grade Diagnostic Values

• Ignition Coil Primary Resistance — expected: 0.62 Ω ± 10% at 20°C (68°F). Failure: A reading of 0 indicates a short, while an infinite (OL) reading indicates an open circuit.
• Ignition Coil Secondary Resistance — expected: 7.0 kΩ ± 15% at 20°C (68°F). Failure: Readings significantly outside this range suggest a faulty coil.
• Fuel Pressure (at idle) — expected: ~58 PSI. Failure: Significantly lower pressure points to a weak fuel pump or clogged filter. The regulator is in the tank.
• Engine Compression — expected: 192 psi (1323 kPa). Failure: Significantly lower pressure in cylinder 2 compared to others indicates a mechanical engine issue (valves, rings, head gasket).
• Spark Plug Gap — expected: 1.0 - 1.1 mm (0.039 - 0.043 in.). Failure: An incorrect gap can lead to a weak or inconsistent spark.

Scan Tool Commands That Help

• Hyundai GDS (Global Diagnostic System): Power Balance Test — This function allows a technician to disable individual cylinders one by one to see the effect on engine RPM. If disabling cylinder 2 causes no change in RPM drop compared to other cylinders, it confirms cylinder 2 is not contributing power, which is useful for verifying the misfire before swapping parts.
• Hyundai GDS (Global Diagnostic System): Misfire Counter — Live data on the GDS or an advanced scan tool can show misfire counts for each cylinder in real-time. This is useful for confirming the misfire is isolated to cylinder 2 and for checking if the misfire moves to another cylinder after swapping components like an ignition coil.

Wiring & Ground Locations

• ECM Connector Pin for Cylinder 2 Ignition Coil — On the main Engine Control Module (ECM) connector.. A document for a similar MPI engine shows the ignition coil control output for cylinder #2 is on Pin 1 of connector CLG-A. A technician can use this to check for a control signal from the ECM with a lab scope, helping to differentiate between a wiring/ECM problem and a faulty coil itself. A break in the wire between this pin and the coil will cause a P0302.

Real Owner Repair Stories

• YouTube Commenter (Vehicle not specified, but had a P0302 code.) — Cylinder 2 misfire code was present.
  ❌ Tried (didn't work) Replaced ignition coils, Replaced spark plugs
  ✅ What actually fixed it The problem was a clogged fuel injector. Using a bottle of Redline fuel injection cleaner in the fuel tank and running the car resolved the misfire code.
• Reddit user on r/Hyundai (2018 Hyundai Elantra, 60k miles) — P0302 code, check engine light.
  ❌ Tried (didn't work) Swapping the spark plug did not resolve the issue.
  ✅ What actually fixed it The issue was a faulty ignition coil. The user noted that after replacing it with an aftermarket coil, the problem returned, and advises that Hyundai vehicles can be sensitive to non-OEM coils.
• NHTSA ODI #11701387 Reporter — An owner reported that even after replacing the battery, all coils, and spark plugs, the P0302 code continued to persist, especially when climbing uphill.

OEM Part Supersession History

• 27301-3C010 → 27301-3C000 — Standard part revision and consolidation by the manufacturer.
  Heads up: The parts are interchangeable. 27301-3C000 is the correct current part number for this application.

Diagnostic Flowchart

Other Known Issues on This Vehicle

Issues unrelated to this code that are worth knowing about as an owner of this generation:

• Timing Cover / Cylinder Head Cover Gasket Oil Leak 🟠 Medium → Shop Engine Cylinder Head — Common on higher mileage engines. Oil may leak externally or into spark plug wells. (Ref: TSB 12-EM-004, TSB 10-EM-006)
• ABS Module Electrical Short 🔴 High — Subject to a major recall. Water can enter the ABS module, creating a fire risk even when the vehicle is off. (Ref: Hyundai Recall 172 / NHTSA 18V026000)
• Rear Crossmember Corrosion 🔴 High — Affects vehicles sold or registered in 'salt belt' states. Corrosion can lead to control arm detachment. (Ref: Hyundai Recall 114 / NHTSA 13V354000)
• Failing Power Steering Pressure Hose 🟠 Medium — The high-pressure hose is known to leak, causing whining noises and a loss of power steering assist. It is a very expensive part from the dealer.
• Malfunctioning Stop Lamp Switch 🟡 Low — Widespread recall issue where the switch fails, causing brake lights to not illuminate or cruise control to not deactivate. (Ref: Hyundai Recall 110 / NHTSA 13V113000)
• Excessive Oil Consumption 🟠 Medium — While more prevalent on other Hyundai engines, some owners of the 3.8L report higher than normal oil consumption, which can foul spark plugs and lead to engine damage if the level is not monitored.

Used vs. New Parts: Buying Guide for This Vehicle

When a used part is the smart pick: For this specific P0302 repair, buying used parts is generally not recommended. The primary causes are wear-and-tear items like ignition coils and spark plugs, which have a finite lifespan. A used coil or injector carries an unknown history and may fail soon after installation.

Donor-vehicle mileage cap: roughly under 50000 miles for the part to have meaningful remaining life.

What to inspect on the donor part:

• For an ignition coil, check for cracks in the plastic housing or corrosion on the electrical connector pins.
• Avoid any parts from an engine bay that is excessively dirty, oily, or shows signs of flood damage.

OEM-only on this vehicle (don't cheap out):

• Ignition Coils: Forum users report that some Hyundai models are sensitive to aftermarket ignition coils, sometimes causing repeat failures or persistent issues. Using OEM or a reputable OE-supplier brand like NGK or Denso is a safer bet.

Aftermarket brands forum-validated for this vehicle:

• NGK (for both spark plugs and ignition coils)
• Denso
• Carquest Premium

Brands owners have reported issues with on this vehicle:

• Unbranded, low-cost ignition coils from online marketplaces are frequently cited as a source of premature failure across many vehicle forums.

Real Owner Stories

Aggregated from forums and TSBs cited above. Mileages and costs reflect what owners reported in those sources.

Related OBD-II Codes

• P0304 — This code indicates a misfire on cylinder 4; it is the companion code used during the diagnostic 'swap test' to confirm if a faulty ignition coil or spark plug from cylinder 2 is the root cause.
• P0300 — A random/multiple cylinder misfire code that may appear if multiple ignition coils or spark plugs are failing simultaneously due to age or oil fouling.
• P0306 — Misfire code for cylinder 6, which is also located on Bank 2 (the front bank) and shares the same environmental wear and ease of access as cylinder 2.
• P0301 — Misfire code for cylinder 1; while located on the harder-to-reach Bank 1, it shares the same ignition coil and spark plug components as cylinder 2.

Frequently Asked Questions