Audi DTC P0174 – PCM software needs to be updated, Vacuum leaks (Intake Manifold Gaskets, vacuum hoses, PCV hoses, etc.), Faulty Mass Airflow (MAF) Sensor, Plugged Fuel Filter or weak Fuel Pump, Plugged or dirty Fuel Injectors
DTC P0174 meaning on Audi
DTC P0174 indicates that the engine control module (ECM) has detected a lean condition in the engine’s air-fuel mixture on bank 2. This means that there is too much air and not enough fuel in the combustion process, which can lead to poor engine performance and increased emissions.
Audi DTC P0174 symptoms
Common symptoms associated with DTC P0174 may include:
- Rough idling or stalling
- Decreased engine power
- Poor fuel economy
- Check Engine Light illuminated
- Unusual engine noises
Audi DTC P0174 causes
Several factors can contribute to the occurrence of DTC P0174, including:
- PCM software needs to be updated
- Vacuum leaks (Intake Manifold Gaskets, vacuum hoses, PCV hoses, etc.)
- Faulty Mass Airflow (MAF) Sensor
- Plugged Fuel Filter or weak Fuel Pump
- Plugged or dirty Fuel Injectors
Audi DTC P0174 seriousness
DTC P0174 is considered a serious issue as it can lead to:
- Engine misfires
- Increased emissions
- Potential engine damage if not addressed
- Failure of emissions testing
How to diagnose DTC P0174 on Audi
To diagnose DTC P0174, follow these steps:
- Use an OBD-II scanner to confirm the DTC and check for any related codes.
- Inspect for vacuum leaks in hoses and gaskets.
- Test the MAF sensor for proper operation.
- Check the fuel system for pressure and flow issues.
- Examine the fuel injectors for clogs or dirt.
How to fix DTC P0174 on Audi step-by-step instructions
To fix DTC P0174, follow these steps:
- Update the PCM software if necessary.
- Repair or replace any vacuum leaks found during inspection.
- Test and replace the MAF sensor if it is faulty.
- Replace the fuel filter if it is plugged.
- Test and replace the fuel pump if it is weak.
- Clean or replace the fuel injectors as needed.
How to erase DTC P0174 on Audi
To erase DTC P0174, follow these steps:
- Connect an OBD-II scanner to the vehicle’s diagnostic port.
- Access the trouble codes menu on the scanner.
- Select the option to clear or erase codes.
- Turn off the ignition and disconnect the scanner.
- Start the engine and monitor for any reoccurrence of the code.
Recommended tools for Audi diagnostics
Explore our expert picks: The Best OBD2 Scanners for 2025
Easy-to-use Multimeter for reliable diagnostics: AstroAI Auto-ranging Multimeter
Some of the links on this page may be affiliate links, which means we may earn a small commission if you make a purchase. This helps us keep our DTC database up to date and provide valuable content for free. We only recommend products that we have tested and believe to be the best in their class.