What P0174 Means on Your 2024 Ram 1500
A P0174 trouble code on your 2024 Ram 1500 indicates that Bank 2 is running with a lean air-fuel mixture. The 2024 Ram 1500 offers several engine options: the 3.6L Pentastar V6 (305 hp), the 5.7L HEMI V8 (395 hp), and the 3.0L Hurricane twin-turbo inline-six (420 hp). On the V6 and V8 engines, Bank 2 is the side that does not contain cylinder 1. A lean condition means there's too much air or not enough fuel on that bank.
This is a code you should take seriously. On a full-size truck that may be used for towing and hauling, engine performance and reliability are critical.
Symptoms
- Check engine light on
- Rough idle
- Hesitation or stumbling during acceleration
- Reduced power, especially under load
- Poor fuel economy
- Possible engine knock under heavy acceleration
Common Causes by Engine
- Vacuum Leak (30% likelihood) – Intake manifold gaskets, vacuum hoses, and PCV connections can leak. The HEMI's large intake manifold has multiple potential leak points.
- Fuel Injector Issue (25% likelihood) – A clogged or failed injector on Bank 2 reduces fuel delivery to those cylinders. The HEMI's MDS (Multi-Displacement System) can cause injector issues on deactivated cylinders.
- MAF Sensor Problem (25% likelihood) – A contaminated or failing MAF sensor underreports airflow, leading to lean fueling across the engine.
- Exhaust Leak Before O2 Sensor (20% likelihood) – An exhaust manifold leak on Bank 2 draws in ambient air past the O2 sensor, falsely indicating a lean condition.
Diagnosis
- Scan all codes – Check for Bank 1 lean (P0171), misfire codes, or cylinder-specific codes that help narrow the bank.
- Check fuel trims – Compare Bank 1 and Bank 2 LTFT values. If only Bank 2 is high, the issue is bank-specific.
- Smoke test – Find vacuum leaks in the intake manifold and associated hoses.
- Test fuel injectors – Use a noid light or injector balance test to check injector operation on Bank 2.
- Inspect exhaust manifolds – Listen for ticking sounds indicating an exhaust leak, especially when cold.
Repair Costs
- Vacuum leak repair – Hose: $50–$200. Intake manifold gasket: $300–$600.
- Fuel injector – Single injector: $100–$250. Full set: $400–$800. Labor: $200–$400.
- MAF sensor – Cleaning: $10. Replacement: $100–$300.
- Exhaust manifold repair – Gasket: $150–$350. Manifold replacement: $400–$900.
DIY Feasibility
The Ram 1500's engine bay offers decent access, especially on the V8. MAF cleaning is simple. Checking for vacuum leaks with soapy water is doable. Fuel injector testing and exhaust manifold work require more tools and experience. The truck's height makes it easy to work on from above without a lift.
Prevention
- Replace the air filter every 20,000–30,000 miles
- Use Top Tier gasoline
- Inspect vacuum hoses and connections regularly
- Consider fuel injector cleaning every 50,000 miles
- Address exhaust ticking sounds promptly