P0174 — System too Lean (Bank 2)
Category: Powertrain Severity: Medium
Updated:
DTC code P0174 means: System too Lean (Bank 2). It falls under the "Powertrain" category, with an estimated severity of Medium. Common causes include vacuum / intake leak, faulty MAF sensor and low fuel pressure; it's worth confirming the diagnosis before replacing parts.
Possible causes
- Vacuum / intake leak
- Faulty MAF sensor
- Low fuel pressure
- Faulty O2 sensor
Symptoms
- Loss of power when accelerating
- Unstable idle
- Higher fuel consumption
- Jerking while driving
How to diagnose it step by step
- If it appears with P0171, look for a common cause (vacuum leak, MAF, pressure).
- If only P0174 is set, look for bank 2 leaks.
- Do a smoke test.
- Clean the MAF.
How to fix it
Clean or replace the MAF/MAP sensor and check for intake leaks.
Estimated repair cost
$10–300 in most cases.
Frequently asked questions
What does DTC code P0174 mean?
System too Lean (Bank 2).
Is code P0174 serious?
Severity Medium. Not urgent, but worth diagnosing to avoid bigger damage.
Can I keep driving with code P0174?
Yes, short term.
Related codes
P0175 P0172 P0171 P0161 P0190 P0157 P0191 P0156 P0155 P0193
Refine by car make
- Audi P0174: Vacuum leaks or MAF.
- BMW P0174: Intake leaks.
- Citroën P0174: MAF/MAP sensor or leak.
- Dacia P0174: MAF/MAP sensor.
- Fiat P0174: MAF/MAP sensor.
- Ford P0174: Vacuum leaks or MAF sensor.
- Honda P0174: Vacuum leaks or MAF/MAP.
- Hyundai P0174: Vacuum leaks or MAF.
- Kia P0174: Vacuum leaks or MAF.
- Mazda P0174: MAF sensor.
- Mercedes-Benz P0174: Intake leaks or MAF.
- Nissan P0174: MAF sensor.
- Opel P0174: Vacuum leaks or MAF.
- Peugeot P0174: Intake leaks or MAF.
- Renault P0174: Intake leaks or MAP/MAF.
- Toyota P0174: Vacuum leaks or MAF.
- Volkswagen P0174: Vacuum leaks or MAF sensor.
- Volvo P0174: MAF sensor.
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