What does code P0174 mean?

P0174 — System too lean, Bank 2. V6/V8 only. Same symptoms as P0171 but on the other cylinder bank. Belongs to the powertrain.fuel-trim system. Severity: warning.

What are the common causes of P0174?

Vacuum leak on Bank 2 intake side; Contaminated MAF sensor (shared between banks); Low fuel pressure — affects both banks; Clogged injectors specifically on Bank 2; Broken Bank 2 O2 sensor connector

Can I drive with code P0174?

Limited: reaching the nearest workshop is fine, but avoid long trips. May progress into a more serious fault.

How do I diagnose P0174?

Read the code and freeze-frame with a scanner, check related-system errors, inspect the components listed (wiring, connectors, sensors). See the "How to diagnose" section above for the full step-by-step.

How do I clear code P0174?

The code can be cleared via an OBD-II scanner (e.g. ELM327 + the Car Diagnostics app): plug the adapter into the OBD port, go to Errors → Clear. If the underlying cause isn't fixed, the code will return within a few drive cycles.

OBD-II Code P0174 — Car Diagnostics Platform

What it means

Common causes

Vacuum leak on Bank 2 intake side
Contaminated MAF sensor (shared between banks)
Low fuel pressure — affects both banks
Clogged injectors specifically on Bank 2
Broken Bank 2 O2 sensor connector
Cracked intake manifold on Bank 2 side
Exhaust leak upstream of Bank 2 O2 sensor
One bank worn faster than the other

How to diagnose

01
Read all stored and pending codes with an OBD-II adapter — get the full picture, not just the one code.
02
Capture freeze-frame data (RPM, coolant temperature, engine load) at the exact moment the code triggered.
03
Inspect the named subsystem with our app's AI explanation — get vehicle-specific causes for your make, model and year.

Decode P0174 on your actual car

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