why does my Ram 1500 DT (2019-Present) have a check engine light with P0174?

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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the vehicle battery to prevent electrical shorts.
• Ensure the vehicle is on a level surface and engage the parking brake.

2. Inspect and Repair Air Intake System

• Tools Required: Screwdriver set, pliers, flashlight.
• Sub-steps:
  1. Visually inspect all components of the air intake system for signs of wear, cracks, or loose connections.
  2. Tighten or replace any damaged clamps or hoses.
  3. Replace any damaged vacuum hoses.
  4. Ensure the air filter is clean; replace if necessary.

3. Clean or Replace MAF Sensor

• Tools Required: MAF cleaner or electrical contact cleaner.
• Sub-steps:
  1. Remove the MAF sensor from the intake duct.
  2. Spray the sensor element with MAF cleaner and allow it to dry.
  3. Reinstall the MAF sensor and ensure all connections are secure.

4. Check Fuel Delivery System

• Tools Required: Fuel pressure gauge and appropriate wrenches.
• Sub-steps:
  1. Connect the fuel pressure gauge to the fuel rail.
  2. Turn the ignition to the "ON" position (do not start the engine) and check the pressure reading; it should match manufacturer specifications.
  3. If pressure is low, inspect the fuel pump and replace the fuel filter as necessary.

5. Inspect and Replace Oxygen Sensors (if needed)

• Tools Required: O2 sensor socket, wrench set.
• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors.
  2. Unplug the electrical connectors and remove the sensors from the exhaust system.
  3. Install new sensors and reconnect the electrical connectors.

6. Verify Intake Manifold Gasket

• Tools Required: Smoke machine (optional) or soapy water.
• Sub-steps:
  1. Perform a smoke test to detect any leaks in the intake manifold gasket.
  2. Replace the intake manifold gasket if leaks are detected.