P0174 Trouble Code Help: Diagnostic & Repair

What Does the P0174 Code Mean?

Code P0174 indicates that there is a lean condition detected by the Engine Control Module (ECM). A lean condition will be created if there is too much air, and not enough fuel, in the air fuel ratio (AFR). The ECM is designed with the capability of adjusting a lean condition back to normal, but only in small to mediocre amounts. If the air fuel ratio requires more compensation to return to normal than the ECU is capable of, code P0174 may be set.

How Serious is the P0174 Code?

Generally, a lean condition is not that serious, and safety while driving should not be affected. However, be aware that there is a possibility of the lean condition being caused by a leak in the intake system. Leaks in the air intake may allow particles to enter the engine, which may be damaging to the vehicle.

Potential Causes of the P0174 Code

Some potential causes of the P0174 code to be set include:

• An air leak after the mass air flow (MAF) sensor, such as a torn intake boot, or bad intake manifold gaskets
• A dirty or faulty mass air flow sensor
• Faulty oxygen sensor
• Incorrect fuel pressure
• Leaking positive crankcase ventilation (PCV) valve
• Clogged exhaust gas recirculation (EGR) Port
• Leaking brake booster

Repairs to Fix the P0174 Code

The following are some possible repairs for the P0174 code, depending on the source of the issue:

• Replacing mass air flow sensor
• Cleaning mass air flow Sensor
• Replacing faulty oxygen sensor
• Replacing PCV valve
• Replacing vacuum line
• Replacing EGR valve
• Replacing brake booster
• Replacing valve cover gasket

Potential P0174 Code Symptoms

Potential symptoms associated with the P0174 code are as follows:

• Increased fuel consumption
• Check Engine Light will come on
• Rough or high idle
• Decreased acceleration *Engine stalling

How a P0174 Inspection Works with YourMechanic

1. When you choose YourMechanic, a mobile mechanic in your area will come to your home or office to perform an inspection, saving you time and money.
2. Here is how a mobile mechanic will inspect your P0174 code:
3. Performs a fuel pressure test
4. Checks the intake system and vacuum lines for leaks
5. Inspects the valve cover for worn hoses or leaks
6. Inspects the PCV valve
7. Tests the mass air flow sensor with a scan tool or multimeter
8. Tests the related oxygen sensor with a scan tool or multimeter

Most Common Mistakes When Diagnosing

The two most common mistakes when diagnosing code p0174 are:

• Replacing a component without first deeming it bad through testing
• Failing to check the intake system for tears or leaks

Inspection & Repair for Code P0174

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.