2014 Mazda P0174: What It Means & Is It Safe to Drive?
P0174 on the 2014 Mazda: System Too Lean (Bank 2). Here's what it means, what usually causes it, what repairs typically cost, and whether it's safe to keep driving.
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What this code means
Same as P0171 but for bank 2. The engine is running too lean on the side that contains cylinder 2.
Common causes on the 2014 Mazda
- Vacuum leaks affecting bank 2
- Faulty MAF or O2 sensor
- Fuel delivery issues
Symptoms
- Check Engine Light
- Rough idle, hesitation
- May appear with P0171 on V6/V8 engines
Typical fixes
- Smoke test for vacuum leaks
- Inspect intake gaskets and hoses
- Check fuel pressure and filter
Repair cost range
For a 2014 Mazda, repairs for P0174 typically fall between $100 and $600, depending on the root cause and labor rates in your area.
Known issues on Mazda
Mazda V6 P0174 Bank 2 lean often comes from a vacuum leak at the intake or a contaminated MAF sensor. On older MZR-3.0 (AJ) V6 engines, the PCV system can deposit oil residue on the MAF sensing element—cleaning resolves the majority of P0174 cases.
Most commonly affected models
Mazda6 V6 2.3L 2003–2008MPV V6 3.0L 2000–2006CX-9 V6 2007–2015