OBD codes / P0174 / Nissan Altima
P0174 on a Nissan Altima
System Too Lean (Bank 2)
VQ35 3.5 V6 Altima.
What P0174 usually means on a Altima
P0174 reports a lean condition on bank 2 and therefore applies to V6 Altimas with two cylinder banks. When it appears alongside P0171, suspect a shared cause such as a dirty MAF or a common vacuum leak rather than two separate problems. A lone P0174 points to a leak specific to that bank. Prolonged lean running can aggravate misfires on the VQ35.
Most likely causes on this model
- Dirty MAF sensor
A contaminated Nissan MAF leans both banks and is common when P0171 and P0174 appear together.
- Vacuum or PCV leak
A shared leak drives both banks lean.
- Bank-2 intake gasket leak
A gasket leak leans only bank 2 on the VQ35.
- Weak fuel delivery
A failing pump starves both banks under load.
What it costs on a Altima
If both banks read lean, clean or replace the MAF and smoke-test for leaks first - inexpensive steps. Intake gaskets on the V6 add labor to reach. Fuel-supply repairs are the costlier, rarer cause.
Year, engine and mileage change the answer. Get a diagnosis for your Altima — it weighs these causes against your exact configuration and real complaint data.
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Nissan Altima problems & recalls by year
Based on widely reported patterns for this model; individual causes vary by year, engine and history. Generic P0174 behavior is covered on the main P0174 page. Confirm with a scan tool before buying parts.