What Does P0174 Mean on Your 2022 Honda Civic?
A P0174 trouble code on your 2022 Honda Civic signals that the engine control module has detected a lean air-fuel mixture on Bank 2. The 2022 Civic is available with a 2.0-liter naturally aspirated four-cylinder producing 158 hp or a 1.5-liter turbocharged four-cylinder making 180 hp. Both are inline-four engines with a single bank, making a P0174 code technically unusual. However, the lean condition it represents is very real and needs to be addressed.
A lean mixture means the engine is receiving too much air or not enough fuel. This can lead to poor performance, rough running, and potential engine damage from the higher combustion temperatures that lean mixtures produce.
Symptoms to Watch For
- Check engine light on
- Rough or shaky idle
- Hesitation during acceleration
- Loss of power
- Engine running hotter than normal
- Occasional misfires or surging at idle
Common Causes on the 2022 Civic
- Vacuum Leak - Cracked or disconnected vacuum hoses, a leaking intake manifold gasket, or a deteriorated PCV hose are the most common cause of lean codes on the Civic. The 11th-generation Civic's engine bay runs warm, which accelerates rubber hose deterioration.
- Dirty MAF Sensor - A contaminated mass airflow sensor underestimates airflow, causing the ECM to deliver insufficient fuel. On the 1.5T engine, oil vapor from the turbo system can coat the sensor over time.
- Weak Fuel Pump - A fuel pump losing pressure cannot deliver enough fuel at higher RPMs or under load. This typically shows up as hesitation during acceleration.
- Faulty Oxygen Sensor - A biased or slow-responding O2 sensor can cause the ECM to lean out the mixture incorrectly.
Diagnostic Steps
- Pull all codes - Scan for all DTCs. Check if P0171 is also stored, which would be more expected for the inline-four configuration.
- Check for vacuum leaks - Inspect every vacuum hose, the intake manifold gasket area, the PCV system, and the brake booster hose. A smoke test is the most thorough approach.
- Clean the MAF sensor - Remove and spray with MAF cleaner. This costs almost nothing and resolves a good percentage of lean codes.
- Review fuel trims - Monitor STFT and LTFT on your scan tool. Positive values above +10% confirm the ECM is adding fuel to compensate for a lean condition.
- Test fuel pressure - Measure fuel pressure at idle and under load. Compare to Honda specifications to rule out a fuel delivery problem.
Repair Costs
The Honda Civic is one of the most affordable cars to repair in the market.
- Vacuum hose replacement - $5 to $25 for parts. Quick DIY fix.
- Intake manifold gasket - $25 to $65 for the gasket, plus $140 to $270 in labor.
- MAF sensor cleaning - $10 to $25 for cleaner.
- MAF sensor replacement - $75 to $170 for the part, plus $50 to $100 in labor.
- Fuel pump replacement - $140 to $320 for the pump, plus $180 to $370 in labor.
- O2 sensor replacement - $55 to $140 for the sensor, plus $60 to $120 in labor.
DIY Feasibility
The Civic is one of the most DIY-friendly cars you can work on. Vacuum hose inspection and replacement require no special tools. MAF sensor cleaning is a 10-minute job. O2 sensor replacement is straightforward with a sensor socket. Even intake manifold gasket replacement is manageable for an intermediate DIYer. Fuel pump work is the most complex job on this list, typically requiring access through or under the rear seat.
Prevention Tips
- Inspect vacuum hoses annually and replace any that show cracks or hardening
- Keep the air filter clean to protect the MAF sensor
- Use quality fuel from reputable stations
- Follow Honda's recommended maintenance schedule
- Do not ignore check engine lights, as lean conditions can cause overheating and engine damage