P0307 on 2013-2020 Dodge Challenger: Cylinder 7 Misfire Causes and Fixes

What's Unique About the 2013-2020 Dodge CHALLENGER

On HEMI V8 engines in the Challenger, a P0307 code can sometimes be more than just a simple ignition issue. These engines, particularly those with the Multi-Displacement System (MDS), are known for potential lifter and camshaft failures. A collapsed lifter can fail to open the valves correctly, leading to a loss of compression and a persistent misfire on that cylinder. A user on a Reddit forum for Challengers confirmed that a P0307 code accompanied by a distinct 'ticking' noise from his 2021 Scat Pack was diagnosed as a failed lifter that had damaged the camshaft, requiring replacement of both. While you should always check the basics like plugs and coils first, be aware that a P0307 accompanied by a ticking noise could point to this more serious mechanical problem.

Diagnostic Flowchart

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

Symptoms You May Notice

• Flashing or solid Check Engine Light.
• Rough idle or engine vibration
• Hesitation or stumbling during acceleration
• Noticeable loss of power.
• Increased fuel consumption
• Engine ticking noise (in case of mechanical failure).
• Difficulty starting the engine.
• Unpleasant fuel smell from the exhaust

Most Likely Causes

1. Faulty Ignition Coil 🔴 High Probability Coil-on-plug ignition systems are common points of failure on many modern engines due to constant heat cycles and vibration. The HEMI engines are no exception.
   How to confirm: Swap the ignition coil from cylinder 7 with another cylinder (e.g., cylinder 1). Clear the codes and drive the vehicle. If the code changes to P0301, the ignition coil is faulty.
   Typical fix: Replace the faulty ignition coil. The OEM Mopar part number is 68238603AA, which supersedes previous numbers like 56029129AF and 68060346AA.
   Est. part cost: $40-$100
2. Worn or Fouled Spark Plug 🔴 High Probability HEMI engines use two spark plugs per cylinder, increasing the number of potential failure points. The recommended replacement interval is often overlooked. For 2009+ 5.7L engines, the OEM Champion plug is a common choice.
   How to confirm: Remove the spark plugs from cylinder 7 and inspect them for wear, carbon buildup, oil fouling, or damage to the electrode/insulator. Compare them to plugs from a working cylinder. Check for correct gap, which should be around 0.044 inches.
   Typical fix: Replace the spark plug(s). It is highly recommended to replace all 16 spark plugs at the same time 🎬 Watch: Step-by-step spark plug and coil replacement on a 6.4 Hemi. for even performance and to avoid future misfires.
   Est. part cost: $10-$25 per plug
3. Faulty Fuel Injector 🟡 Medium Probability
   How to confirm: After ruling out the ignition system, you can swap the fuel injector from cylinder 7 with another cylinder. This is more labor-intensive. A professional can also perform a fuel injector balance test. TSB 14-003-22 REV. A was issued for some 2021 6.4L models for high-flow injectors causing misfires, indicating injectors can be a known issue.
   Typical fix: Replace the faulty fuel injector and its seals.
   Est. part cost: $70-$150
4. PCM Software Update Needed ⚪ Low Probability Multiple Technical Service Bulletins (TSBs) have been issued by Dodge for software updates to address false or intermittent misfire codes. TSB 18-046-15 and 18-073-20 specifically list P0307 along with air-fuel imbalance codes (P219A/P219B) as being potentially resolved by a PCM flash.
   How to confirm: A Dodge dealership or a qualified shop with access to OEM software (wiTECH) can check if your vehicle's PCM has the latest calibration by referencing the TSBs.
   Typical fix: Update the Powertrain Control Module (PCM) software. This is a labor-only charge.
   Est. part cost: $100-$200 (labor for flashing)

Rare But Worth Checking

• Failed Camshaft Lobe / Lifter ('Hemi Tick'): This is a known, albeit less common, issue on HEMI engines, especially those with MDS. A distinct ticking or tapping sound from the engine is a strong indicator. The roller on a lifter can seize, grinding down the camshaft lobe and reducing valve lift, which causes a loss of compression and a persistent misfire. A user on r/Challenger confirmed a P0307 code on their 2021 Scat Pack was the result of a failed lifter that damaged the camshaft. This requires significant mechanical repair, including removing the cylinder heads.
• Low Engine Compression: Caused by issues like a leaking valve, worn piston rings, or a damaged head gasket. A compression test and a cylinder leak-down test are required to diagnose this. This can be the result of a failed lifter/cam as described above.
• Vacuum Leak: A vacuum leak near the intake manifold runner for cylinder 7 could lean out the mixture enough to cause a misfire, though this would often be accompanied by other lean codes or a hissing sound.

Diagnosis Steps

1. Read all stored trouble codes with an OBD-II scanner. Note any other codes present, especially P0300, P219A/B, or P2097.
2. Identify cylinder 7. On HEMI V8s, it is the rearmost cylinder on the driver's side (left side of the engine bay).
3. Swap the ignition coil from cylinder 7 with an easily accessible cylinder, like cylinder 1 (front of the driver's side). The Mopar part number is 68238603AA.
4. Clear the codes and test drive the vehicle. If the misfire code moves to P0301, the coil is bad. Replace it.
5. If the code remains P0307, swap the spark plugs from cylinder 7 with cylinder 1. Remember HEMIs have two plugs per cylinder. Clear codes and re-test. If the code moves to P0301, the spark plug(s) are bad. Replace all 16 for best results.
6. If the code remains P0307, inspect the wiring and connector for the ignition coil and fuel injector on cylinder 7 for any damage, corrosion, or looseness.
7. Listen carefully to the engine at idle. A rhythmic ticking or tapping noise, especially if it's new, could indicate the infamous 'Hemi tick' from a failing lifter.
8. If a ticking noise is present, or if ignition/spark has been ruled out, a mechanical issue is likely. Perform a compression test and cylinder leak-down test on cylinder 7 to check for internal engine problems.
9. If no obvious cause is found, check with a dealership for any open recalls or applicable TSBs, such as TSB 18-046-15 or 18-073-20 for a PCM software update.

Parts You'll Likely Need

• Ignition Coil (OEM #68238603AA) — This is the most frequent point of failure for a single-cylinder misfire due to constant exposure to heat and vibration. This part number is a common replacement for all modern HEMI V8s.
  Trusted brands: Mopar, NGK, Delphi
  OEM price range: $60-$100
  Aftermarket price range: $40-$80
• Spark Plug (OEM #SP149125AE (for 6.4L), RE14MCC4 (older 5.7L)) — Spark plugs are a routine maintenance item and a common cause of misfires as they wear out. HEMI engines use 16 plugs, increasing the chance of a failure.
  Trusted brands: NGK, Champion
  OEM price range: $15-$25
  Aftermarket price range: $10-$20
• Fuel Injector — Less common than ignition parts, but a clogged or failed injector will directly cause a misfire on its corresponding cylinder. TSB 14-003-22 REV. A addresses faulty injectors on some 6.4L models.
  Trusted brands: Mopar, Bosch
  OEM price range: $120-$200
  Aftermarket price range: $70-$150

Related Codes That Often Appear With This One

• P0300 — If the misfire condition is intermittent or begins to affect other cylinders, a P0300 (Random/Multiple Cylinder Misfire) may be stored.
• P219A / P219B — Bank 1/2 Air-Fuel Ratio Imbalance. TSB 18-073-20 and 18-084-16 explicitly link these codes with P0307, noting that a PCM software update may resolve them simultaneously.
• P2097 — Post Catalyst Fuel Trim System Too Rich. A misfire can cause unburnt fuel to enter the exhaust, leading the O2 sensor to report a rich condition. A Reddit user reported this code along with P0307 on a low-mileage 2023 Challenger Redeye.

Technical Service Bulletins (TSBs) & Recalls

• 1807320: Flash: Powertrain Control Module (PCM) Updates. Addresses P0307 along with P219A/P219B and other codes.
• 18-084-16: Similar to the above, a PCM flash to address P0307 and air-fuel imbalance codes.
• 18-046-15: PCM flash for engine buck/misfire, specifically mentioning P0307 and air-fuel imbalance codes.
• 14-003-22 REV. A: Addresses misfires (including P0307) on 2021 6.4L engines caused by high-flow fuel injectors from a specific manufacturing batch.

Platform-Specific Known Issues

• HEMI Lifter/Camshaft Failure: Some 5.7L and 6.4L HEMI engines can experience failure of the roller lifters, particularly on cylinders that are deactivated by the Multi-Displacement System (MDS). The lifter's roller can seize, grinding down the camshaft lobe and reducing valve lift, which causes a loss of compression and a persistent misfire.

Mechanic-Grade Diagnostic Values

• Fuel Injector Resistance — expected: Approximately 11.5 - 12.5 ohms at room temperature.. Failure: A significantly lower reading (e.g., below 1 ohm) or a completely open circuit (infinite resistance) indicates a failed injector.

Hidden / Shadow Codes Worth Checking

• Mode $06 Misfire Counts: While not a 'hidden code' in the proprietary sense, Mode $06 data on an advanced scanner can show misfire counts per cylinder before they reach the threshold to set a P0307 trouble code. This allows a technician to see if cylinder 7 is misfiring intermittently even if the Check Engine Light isn't on. (see via An OBD-II scanner that supports Mode $06 data.)

Scan Tool Commands That Help

• wiTECH (OEM) or advanced aftermarket scanner: Cylinder Contribution / Power Balance Test — Use this after basic checks (plugs, coils) are inconclusive. The tool disables one cylinder at a time and measures the RPM drop. If disabling cylinder 7 causes little or no RPM drop compared to other cylinders, it confirms that cylinder 7 is not contributing power, pointing to a fuel, spark, or compression issue on that specific cylinder.
• Advanced aftermarket scanner: Injector Kill Test — This function allows you to disable individual fuel injectors. If you disable the injector for cylinder 7 and the engine's running condition does not change, it confirms the injector was not working in the first place.

Wiring & Ground Locations

• Cylinder 7 Location — On all 5.7L, 6.2L, and 6.4L HEMI V8 engines, the cylinders on the driver's side (Bank 1) are numbered 1, 3, 5, 7 from front to back. Cylinder 7 is the rearmost cylinder on the driver's side.. Correctly identifying cylinder 7 is the first step for any diagnosis, ensuring you are testing and replacing parts on the correct cylinder.

Real Owner Repair Stories

• YouTube user 'greg's automotive' (Dodge Challenger (year not specified) with 3.6L V6, but diagnostic process is identical for a V8.) — Check engine light with codes P0300, P0306, and P0206. Car was shaking and losing power.
  ❌ Tried (didn't work) Initial diagnosis pointed to cylinder 6.
  ✅ What actually fixed it The owner performed an 'injector kill test' and found no change when disabling cylinder 6. He then tested the injector's resistance and found it was 0.5 ohms, while a good injector was 11.6 ohms. Replacing the faulty fuel injector on cylinder 6 resolved all codes and symptoms. This confirms a failed injector as a direct cause for a specific cylinder misfire code.

OEM Part Supersession History

• 56029129AA, 56029129AB, 56029129AF, 68060346AA → 68238603AA — Standard part evolution for improved reliability or manufacturing changes.

Model Year Variations Within This Range

• 2015-2020: The 2015 model year marked a major refresh. The older 5-speed automatic was replaced with a ZF 8-speed automatic (ZF8HP70), offering faster shifts and better fuel economy. The 6.4L V8 received a power increase to 485 hp from 470 hp due to a revised intake and tuning. The exterior and interior were also significantly updated.
• 2015 (early production): TSB #18-046-15 applies specifically to 2015 Challengers built on or before April 29, 2015, equipped with the 5.7L engine. These vehicles may have a PCM software version that can falsely trigger code P0307, which can be resolved with a software update.