What Does P0174 Mean on Your 2024 Nissan Altima?
A P0174 trouble code on your 2024 Nissan Altima indicates the engine control module (ECM) has detected a lean air-fuel mixture on Bank 2. The engine is receiving more air than fuel in the combustion mix. The 2024 Altima comes with a 2.5-liter four-cylinder engine producing 188 horsepower. Since this is an inline four-cylinder with a single bank, the P0174 designation may relate to how Nissan maps sensor channels, but the lean condition itself is real and should be investigated.
As a current model year vehicle, your 2024 Altima is under full Nissan warranty coverage. Your first call should be to the dealership.
Common Symptoms You May Notice
- Check engine light on
- Rough or unstable idle
- Hesitation during acceleration
- Reduced fuel economy
- Engine surging at steady speeds
- Occasional stalling at stops
Most Likely Causes of P0174 on the 2024 Altima
- Vacuum or Intake Leak - A loose intake boot, cracked vacuum hose, or improperly sealed connection can let unmetered air past the MAF sensor.
- ECM Software Issue - New model software calibrations may need refinement. Nissan may have TSBs addressing fuel trim concerns.
- MAF Sensor Contamination - Even new vehicles can have MAF contamination from manufacturing debris or aftermarket filter products.
- Oxygen Sensor Defect - A factory-defective O2 sensor can provide incorrect exhaust gas data.
How to Diagnose the Problem
- Scan codes - Confirm P0174 and check for related codes.
- Check for TSBs - Ask your Nissan dealer about applicable service bulletins.
- Monitor fuel trims - High positive LTFT confirms the lean condition.
- Schedule dealer service - Recommended for warranty vehicles.
Repair Options and Cost Breakdown
- Warranty repair - $0 for covered issues.
- Vacuum hose repair - $10 to $40 out of warranty.
- MAF sensor cleaning - $8 to $15.
- MAF sensor replacement - $90 to $200, plus $50 to $100 labor.
- O2 sensor replacement - $100 to $230, plus $80 to $150 labor.
- ECM reflash - $0 under warranty.
Can You Fix This Yourself?
For a 2024 model, take it to the Nissan dealer. All warranty-related repairs will be handled at no cost. A quick visual check of the intake connections is fine, but do not replace parts yourself as it could affect your warranty coverage.
Prevention Tips
- Use the factory air filter
- Follow the Nissan maintenance schedule
- Use quality fuel from reputable stations
- Do not ignore check engine lights
- Keep dealer service appointments current