What P0174 Means on Your 2021 Honda HR-V
A P0174 code on your 2021 Honda HR-V indicates the engine control module has detected a lean air-fuel mixture on Bank 2. The 2021 HR-V uses a 1.8-liter naturally aspirated inline-four engine producing 141 hp and 127 lb-ft of torque, paired with a CVT. Since this is an inline-four with only one cylinder bank, a P0174 code is unusual. The lean condition it represents is genuine, though the Bank 2 designation may reflect a sensor mapping issue in the ECM.
A lean condition means the engine is getting too much air or too little fuel. This can cause rough running, reduced performance, and elevated temperatures that risk engine damage.
Symptoms
- Check engine light on
- Rough or uneven idle
- Hesitation or stumbling on acceleration
- Reduced power
- Engine running warm
- Intermittent misfires
Common Causes
- Vacuum Leak - Cracked vacuum hoses, a leaking intake manifold gasket, or deteriorated PCV hose. This is the most common cause on the HR-V's 1.8L engine.
- Dirty MAF Sensor - Contamination on the MAF element causes it to underreport airflow.
- Weak Fuel Pump - A pump losing output cannot keep up with fuel demand, especially during acceleration.
- Failing O2 Sensor - An inaccurate sensor causes incorrect fuel trim corrections.
Diagnostic Steps
- Read all codes - Check for P0171 and companion codes.
- Check for vacuum leaks - Inspect all hoses, gaskets, and PCV components.
- Clean the MAF sensor - Remove and spray with dedicated cleaner.
- Monitor fuel trims - Positive STFT/LTFT above +10% confirm lean running.
- Test fuel pressure - Compare to Honda specifications at idle and under load.
Repair Costs
The HR-V is Honda's most affordable SUV, and repair costs reflect that.
- Vacuum hose replacement - $5 to $20. Easy DIY.
- Intake manifold gasket - $20 to $55, plus $120 to $240 labor.
- MAF sensor cleaning - $10 to $25.
- MAF sensor replacement - $70 to $155, plus $50 to $90 labor.
- Fuel pump replacement - $120 to $280, plus $160 to $320 labor.
- O2 sensor replacement - $50 to $130, plus $60 to $110 labor.
DIY Feasibility
The HR-V is compact but mechanically straightforward. Vacuum hose inspection, MAF cleaning, and air filter replacement are all easy DIY jobs. O2 sensor replacement is manageable with a sensor socket. The fuel pump requires more effort but the HR-V is not overly complex.
Prevention Tips
- Inspect vacuum hoses regularly for cracks
- Replace the air filter on schedule
- Use quality fuel
- Follow Honda's maintenance intervals
- Do not ignore check engine lights