what causes P0174 code in my Ram 1500 DT (2019-Present) and how to fix it?

Learn how to diagnose and fix P0174 lean fuel condition in Ram 1500 DT. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather tools: OBD-II scanner, multimeter, vacuum gauge, smoke machine (optional), basic hand tools, safety glasses, and gloves.
• Disconnect the negative battery terminal to avoid electrical shorts.

2. Inspect and Repair Air Intake System

• Sub-steps:
  1. Visually inspect the air intake hoses and connections for cracks or loose fittings.
  2. Tighten any loose clamps or connections.
  3. Replace any damaged hoses with OEM or equivalent parts.

3. Clean or Replace MAF Sensor

• Sub-steps:
  1. Locate the MAF sensor in the air intake duct.
  2. Disconnect the electrical connector and unscrew the sensor from the duct.
  3. Clean the MAF sensor using MAF cleaner spray (do not use other cleaners).
  4. Reinstall the sensor and reconnect the electrical connector.

4. Check and Repair Vacuum Leaks

• Sub-steps:
  1. Use a smoke machine to introduce smoke into the intake system to identify leaks.
  2. Inspect vacuum lines and intake manifold gaskets for signs of leakage.
  3. Replace any damaged vacuum lines or gaskets.

5. Inspect and Test Fuel System

• Sub-steps:
  1. Connect a fuel pressure gauge to the fuel rail test port.
  2. Start the engine and check that the fuel pressure meets manufacturer specifications (typically around 50-60 psi).
  3. Replace the fuel filter if fuel pressure is low or if it has not been replaced in accordance with the maintenance schedule.

6. Inspect Oxygen Sensors

• Sub-steps:
  1. Locate the oxygen sensors on the exhaust system (upstream and downstream of the catalytic converter).
  2. Use a multimeter to test the sensor's voltage output (should fluctuate between 0.1V to 0.9V).
  3. Replace any faulty oxygen sensors with OEM or equivalent parts.