P0174high severityPowertrain
System Too Lean Bank 2
on 2017 Mazda Mazda3 2.0L I4 · FWD
What this code means
The long-term fuel trim for Bank 2 has exceeded the positive limit, indicating lean running on Bank 2.
Symptoms
- Check Engine Light
- Rough idle
- Hesitation
- Possible misfires
Common causes
- Vacuum leak Bank 2 side
- Low fuel pressure
- Faulty MAF sensor
- Exhaust leak Bank 2
- Clogged injector Bank 2
Diagnostic steps
- Check fuel trim Bank 2
- Smoke test Bank 2 intake
- Test fuel pressure
- Test MAF sensor
- Check for exhaust leaks Bank 2
Repair notes
Same diagnostic approach as P0171 but focused on Bank 2.
Other Powertrain codes on this vehicle
P0001
Fuel Volume Regulator Control Circuit/Open
P0002
Fuel Volume Regulator Control Circuit Range/Performance
P0003
Fuel Volume Regulator Control Circuit Low
P0004
Fuel Volume Regulator Control Circuit High
P0010
Intake Camshaft Position Actuator Circuit/Open Bank 1
P0011
Intake Camshaft Position Timing Over-Advanced Bank 1
P0012
Intake Camshaft Position Timing Over-Retarded Bank 1
P0013
Exhaust Camshaft Position Actuator Circuit/Open Bank 1
P0014
Exhaust Camshaft Position Timing Over-Advanced Bank 1
P0015
Exhaust Camshaft Position Timing Over-Retarded Bank 1