What P0174 Means on Your 2020 Dodge Challenger
A P0174 code on your 2020 Dodge Challenger means Bank 2 is running too lean. The 2020 Challenger offers the 3.6L Pentastar V6 (305 hp), 5.7L HEMI V8 (375 hp), 6.4L HEMI V8 (485 hp), and the supercharged 6.2L Hellcat (717 hp). On all V-configuration engines, Bank 2 is the passenger side. Too much air or too little fuel on those cylinders triggers this code.
The Challenger is a performance car, and running lean is particularly risky under hard driving. The combination of lean mixture and high RPM can cause detonation and serious engine damage.
Symptoms
- Check engine light on (may flash under hard acceleration)
- Rough or inconsistent idle
- Loss of power
- Decreased fuel economy
- Hesitation or stumbling
- Possible pinging or knocking under load
Common Causes
- Vacuum Leak (30% likelihood) – Intake manifold gaskets and vacuum lines. HEMI intake systems have multiple sealing surfaces.
- Exhaust Manifold Leak (25% likelihood) – Broken HEMI exhaust manifold bolts are a well-known issue. A leak near the Bank 2 O2 sensor creates false lean readings.
- MAF Sensor Contamination (25% likelihood) – Aftermarket cold air intakes with oiled filters are popular on Challengers and frequently contaminate MAF sensors.
- Fuel System Issue (20% likelihood) – Clogged injectors or fuel pump weakness. MDS-equipped V8s can develop injector carbon buildup.
Diagnosis
- Scan codes – Check for companion codes and bank-specific data.
- Compare fuel trims – Bank 2 LTFT significantly higher than Bank 1 points to a bank-specific cause.
- Listen for exhaust ticking – Cold-start ticking on the passenger side indicates manifold bolt failure.
- Smoke test – Find vacuum leaks in the intake.
- Test MAF and fuel pressure – Verify proper readings.
Repair Costs
- Vacuum leak – $80–$500.
- Exhaust manifold – Bolt repair: $200–$500. Manifold replacement: $400–$900.
- MAF sensor – Cleaning: $10. Replacement: $80–$250.
- Fuel injector – $150–$500.
DIY Feasibility
The Challenger has a strong enthusiast community with excellent DIY guides. MAF cleaning is a quick job. Exhaust manifold bolt repair requires patience and the right extraction tools. The engine bay is manageable on V6 and 5.7L models, tighter on the 6.4L and Hellcat.
Prevention
- Use premium fuel on all V8 models
- Avoid oiled aftermarket air filters that contaminate the MAF
- Inspect exhaust manifold bolts at every oil change
- Follow the maintenance schedule
- Avoid sustained high-RPM driving if you notice lean symptoms