P0172 Code: Dodge Charger (2021-2023) - Causes, Symptoms & Fixes

Important data note upfront

• Based on the provided NHTSA data snapshot for 2021–2023 Dodge Charger, there are no owner complaints recorded for P0172, and no recalls found in the NHTSA database for this combination. Therefore, no official recalls or TSBs are cited here. No complaint counts are available to indicate how common this DTC is in this specific model year range.
• This guide uses general automotive knowledge to explain P0172 and how it tends to appear on Dodge Chargers, along with practical diagnostic steps, regardless of the absence of official complaint/recall data in the supplied dataset.
• P0172 means “System Too Rich Bank 1” and indicates the engine control module has detected excess fuel trim on Bank 1 over time. In real-world driving, it can come from sensor faults, fuel delivery issues, or intake/air-system problems, and it may impact fuel economy and emissions if not addressed.

CODE MEANING AND SEVERITY

• What the code means: P0172 = System Too Rich Bank 1. The PCM (engine computer) has detected that the long-term fuel trim for Bank 1 is adding too much fuel (i.e., the engine is consistently running richer than commanded on Bank 1).
• Bank designation: On a V-shaped Dodge Charger (for example, V6 or V8 configurations), Bank 1 is the side of the engine that contains cylinder 1. (Bank 2 is the opposite side.)
• Severity and symptoms you might notice:
  • Reduced fuel economy (noticeable drop in mpg).
  • Black or dark exhaust smoke or strong fuel smell.
  • Rough idle or occasional stalling, especially at startup or idle.
  • Check Engine Light (CEL) illuminated and DTC P0172 stored.
  • Potential catalytic converter stress if the condition persists.
• Data interpretation tip: If you can pull freeze-frame data or live fuel trims, LTFT on Bank 1 that remains elevated (often +10% to +25% or higher, and/or STFT values that swing toward positive) supports P0172 as a persistent issue rather than a temporary fault.

COMMON CAUSES ON DODGE CHARGER

The following items commonly contribute to a P0172 condition on Chargers (2021–2023), though actual causes vary by vehicle and fuel system configuration:

• Dirty or faulty MAF sensor (mass airflow): A contaminated or failing MAF can over-report air mass, causing the PCM to richen fuel to compensate.
• Vacuum leaks or intake leaks that paradoxically cause misreadings or abnormal trims: In many engines, vacuum leaks tend to cause lean codes (P0171/P0174), but accompanying failures (sensor faults, misreads) can still yield P0172 patterns in some drive regimes.
• Upstream oxygen sensor (Bank 1 Sensor 1) fault or degraded signal: If the sensor fools the PCM into thinking the exhaust is lean, the PCM may compensate by adding fuel, which can trigger P0172.
• Downstream O2 sensor(s) or misreadings: A faulty downstream sensor can mask the real air/fuel ratio and cause erroneous fuel trim adjustments.
• Fuel delivery issues:
  • Over-fueling due to high fuel pressure (faulty fuel pressure regulator, weak fuel pump, clogged return path in some configurations, or injector leakage).
  • Stuck-open or leaking fuel injectors on Bank 1 (or one or more injectors on Bank 1) delivering excess fuel.
  • Contaminated or poor-quality fuel, or ethanol-related issues causing abnormal trims.
• PCM/software or sensor calibration issues: Infrequent but possible in modern vehicles; a software update or calibration fix can resolve persistent trim anomalies.
• EVAP system interaction (purge valve/solenoid) in some cases can contribute to abnormal trim if the purge flow interacts with engine load in an unexpected way, though this is a less common primary cause for P0172 than fuel delivery or sensor faults.
• Other sensors: MAP sensor (in some engines) or intake air temperature sensor faults can alter air-fuel calculations and fuel trims.
• Mechanical issues that mimic rich conditions: For example, a stuck closed-loop or sensor fault causing the engine to command rich fueling, or, less commonly, misfire-related fuel trim behavior can appear as P0172.

SYMPTOMS

• Illuminated Check Engine Light with P0172 code.
• Noticeable drop in fuel economy.
• Engine may feel “rough” at idle or under light load.
• Possible strong fuel odor near the exhaust or on startup.
• Exhaust may produce darker smoke under acceleration if the vehicle runs rich.
• Idle quality variations and occasional hesitation during acceleration.

DIAGNOSTIC STEPS

A systematic approach to diagnosing P0172 on a 2021–2023 Dodge Charger:

A. Verify DTC and data

• Confirm the P0172 code in the scanner and note freeze-frame data, especially:
  • Long-term fuel trim (LTFT) on Bank 1.
  • Short-term fuel trim (STFT) on Bank 1.
  • O2 sensor readings (upstream bank 1 sensor 1 and downstream bank 1 sensor 2, if available).
• If LTFT is elevated (positive) on Bank 1 and STFT is positive under various load conditions, proceed with fuel/air path checks; if LTFT is not elevated, recheck the data or consider sensor faults.

B. Inspect for obvious causes

• Visual inspection of air intake and vacuum paths:
  • Check for cracked hoses, torn vacuum lines, PCV system hoses, and intake manifold gaskets.
  • Confirm the air filter is clean and seated correctly.
• Inspect the EVAP purge valve and hoses for leaks or sticking operation (a sticking purge valve can cause unexpected rich/lean transitions in some engines).

C. MAF sensor inspection and air-path integrity

• If accessible, remove the MAF sensor and inspect for contamination (oil, dirt, water intrusion). Clean with a MAF-safe cleaner if dirty; do not use harsh cleaners or mechanical scrubbing.
• Reinstall and clear codes; test drive to see if P0172 reappears.
• If MAF is suspected faulty and cleaning does not help, replace the MAF sensor (part cost roughly in the mid-range of the diagnostic options).

D. O2 sensor evaluation

• Upstream O2 sensor (Bank 1 Sensor 1): Test sensor switching behavior with the engine at operating temperature. A healthy sensor should switch between approximately 0.1–0.9 volts rapidly with engine load. Slow or stuck readings can cause incorrect fuel trims.
• Downstream O2 sensor (Bank 1 Sensor 2): Usually monitors post-catalytic oxygen content. If this sensor is failing, it can mask or exaggerate fuel-trim behavior. Compare readings to upstream sensor behavior.
• Consider replacing a faulty upstream O2 sensor if readings are abnormal after cleaning MAF and confirming no vacuum leaks.
• Note: In some vehicle setups, you may find multiple O2 sensors on Bank 1 (e.g., Sensor 1 and Sensor 2). Replace the one indicated by diagnostics or the one showing poor signal quality.

E. Fuel system check

• Fuel pressure test:
  • Connect a fuel pressure gauge (engine running) and compare to the factory spec for your exact engine (check service data for your Charger’s engine variant). If pressure is higher than spec or fluctuates abnormally, suspect fuel pressure regulator, pump, or pressure relief valve issues.
  • In modern direct-injected systems, some fuel pressure regulators are integrated in the pump assembly; replacing the pump assembly may be required if the regulator is not serviceable separately.
• Inspect fuel injectors (Bank 1):
  • Listen for injector clicks with a mechanic’s stethoscope (not always definitive but can help identify obvious leaks or stuck injectors).
  • Consider a fuel injector balance test or a professional cleaning if injector leakage or clogging is suspected.
• Fuel quality and contaminants: Ensure you’re not running low-quality fuel or contaminated fuel.

F. Check for misfires and ignition-related factors

• Scan for misfire codes (P0300-series) that may accompany or mimic P0172; a persistent misfire can cause abnormal fuel trims.
• Inspect spark plugs, ignition coils, and related wiring for proper operation (especially if the engine is older or has high mileage).

G. PCM and calibration considerations

• If all sensors test within normal ranges and fuel trims remain elevated, a software/calibration issue could be suspected. Check with a Dodge dealer or a qualified shop for any published service bulletins, updates, or reflash campaigns relevant to the engine family in your Charger. (No official recalls were cited in the provided data.)

H. If no obvious causes are found

• Consider performing a smoke test to check for hidden vacuum leaks or intake leaks you might not easily see.
• Re-check all connections to sensors (MAF, MAP/MAP sensor, O2 sensors), and ensure ground circuits are solid.
• If persistent, a professional diagnosis with advanced lab equipment may be required to pinpoint a 0.5–1% difference in air/fuel calculation that is not easily observable with a basic scan tool.

RELATED CODES

• P0171: System Too Lean Bank 1 (often appears alongside P0172 in diagnostics or as a separate lean condition).
• P0174: System Too Lean Bank 2.
• P0173: System Too Rich Bank 2 (less common in this context but part of the related family in many vehicles).
• P0175: System Too Rich Bank 2.
• Other related sensor/fuel-trim codes you might see during diagnosis:
  • P0131/P0132/P0133 (O2 sensor circuit faults for Bank 1 Sensor 1, etc.)
  • P0151/P0152 (O2 sensor faults on Bank 2, if applicable)
  • P0300 (Random/Multiple Misfire Detected) if a misfire is contributing to abnormal fuel trim.

REPAIR OPTIONS AND COSTS (2025 PRICES)

Note: Prices vary by region, shop, and exact Charger variant (3.6L V6 vs. Hemi V8, etc.). The ranges below reflect typical consumer repair costs in 2025, including parts and labor. Labor times are approximate and can vary by vehicle condition and technician.

• Do-it-yourself (DIY) options (low cost, if you have appropriate tools):

  • MAF sensor cleaning and reinstallation: $0–$20 for cleaner; labor 0 if done at home.
  • Air filter replacement: $10–$40 for parts; no labor if DIY.
  • Visual vacuum/PCV hose inspection and replacement: $5–$50 for parts; no labor if DIY.
  • O2 sensor inspection (no replacement): Free diagnostic time if you have a scan tool that can monitor sensors; otherwise $50–$100 for basic tools.

• Moderate-cost repairs (labor and parts):

  • Clean/replace MAF sensor (if cleaning fails): $60–$180 parts (MAF) + $60–$150 labor.
  • Upstream O2 sensor replacement (Bank 1 Sensor 1): $120–$260 parts; $60–$120 labor.
  • Downstream O2 sensor replacement (Bank 1 Sensor 2): $120–$220 parts; $60–$120 labor.
  • EVAP purge valve replacement: $120–$250 parts; $60–$120 labor.

• Higher-cost repairs (diagnostic-driven; parts widely vary):

  • Fuel injector cleaning or replacement (Bank 1; multiple injectors if needed): $60–$120 per injector for cleaning; replacement injectors typically $150–$350 per injector plus labor. If multiple injectors are replaced, total can run $600–$1,800.
  • Fuel pump replacement (if fuel delivery is the root cause and access is required): $400–$900 parts; $200–$400 labor.
  • Fuel pressure regulator (if separate from the pump in this design): $100–$300 parts; $60–$150 labor.
  • PCM/ECU replacement and programming (rare but possible): $600–$1,500 parts plus $100–$250 programming/diagnostic fee.

• Biggest driver of cost: The exact engine variant in your Charger (3.6L V6, 5.7L Hemi, 6.4L, or other), the number of affected cylinders/injectors, and whether the part is accessible without removing major components.

DIY VS PROFESSIONAL

• DIY-friendly tasks (if you have basic tools and experience):
  • MAF cleaning and air filter replacement.
  • Visual inspection of intake/vacuum hoses and PCV system.
  • Basic O2 sensor checks with a scan tool; swapping an O2 sensor if the fault is clear and you have proper replacement parts.
  • Simple vacuum leak testing with smoke kit (if you have access).
• Tasks typically better left to a professional:
  • Accurate fuel pressure testing and diagnosing fuel-delivery problems.
  • Injector balance testing and replacement (requires specialized tools for flow testing or high-level inspection).
  • PCM/software updates or reprogramming.
  • Thorough diagnosis when multiple sensors could be implicated, or when dealer-level scan tools are required to confirm fault codes and calibrations.
• Practical approach: Start with non-invasive, low-cost checks (MAF, vacuum leaks, O2 sensor signal checks, fuel quality) and only move to higher-cost parts if data strongly points in that direction and you have the right tools.

PREVENTION

• Regular maintenance to minimize fuel-trim instability:
  • Replace the air filter on schedule; ensure the intake path is clean and free of leaks.
  • Periodically inspect and clean the MAF sensor if your vehicle has a history of dirty MAF readings or you operate in dusty/dirty environments.
  • Use high-quality fuel and avoid ethanol-heavy blends when not appropriate; ensure you refuel at reputable stations to avoid contaminated fuel.
  • Use a trusted fuel system cleaner occasionally if recommended by your vehicle manual or technician.
  • Keep the EVAP system sealed and functioning (repair any cracked hoses, leaky purge valves, or faulty canisters).
  • Address misfires promptly; misfires can complicate fuel trim calibration and trigger P0172 or related codes.
  • Keep software up to date if a dealer has published recommended calibrations for your engine family.
  • Periodic inspection of spark plugs, ignition coils, and wiring (especially with older engines or those with high mileage).

Important data caveat

• The provided data indicates no NHTSA complaints and no recalls for this DTC in the 2021–2023 Charger window. No official recall or TSB references are cited here. This means there is no publicly posted official remedy or bulletin to reference from the supplied data. Real-world prevalence, specific DO/TSB recommendations, or model-year-specific guidance beyond general diagnostic principles would require corroboration from service literature or dealer bulletins outside the supplied dataset.
• If after performing the diagnostic steps you confirm no obvious sensor or fuel-delivery fault, and the P0172 persists, consider contacting a Dodge dealer or an automotive technician with access to service information for your exact Charger engine variant to check for any recent software updates or recall-related fixes that may not be reflected in the provided dataset.