P0171 on a Nissan: Causes, Fixes & Repair Cost

🟠 Moderate severity · drivable

A Nissan with P0171 is drivable short-term, but a lean mixture can cause misfires and should be fixed soon.

What P0171 means on a Nissan

On a Nissan, P0171 means bank 1 is running lean — too much air or not enough fuel — and the ECM has reached its limit adding fuel. Nissan's computer watches the MAF sensor and oxygen sensors, and a lean mixture past the correction limit sets P0171.

Is P0171 common on Nissans?

P0171 is very common on Altimas, Sentras, and Rogues with the 2.5L engine. A failing MAF sensor is a classic Nissan cause, along with vacuum leaks in the intake plumbing.

Commonly reported on: Altima, Sentra, Rogue, Frontier.

Symptoms

Check engine light on
Rough or surging idle
Hesitation when accelerating
Worse fuel economy

Common causes

most common: Dirty or failing MAF sensor
common: Vacuum leak (intake boot, hoses)
common: Worn PCV valve
less common: Weak fuel pump or clogged fuel filter

How to fix it

Fix	DIY?	Typical cost
Clean the MAF sensor with MAF cleaner	Yes	$10–20
Replace the MAF sensor if cleaning doesn't help	Yes	$100–300
Inspect and repair vacuum leaks	Yes	$10–100
Replace a weak fuel pump or clogged fuel filter	Mechanic	$300–700

Frequently asked questions

Can I drive my Nissan with a P0171 code?

Yes for a short time, but a lean engine runs hotter and can misfire. Fix it soon to avoid damaging the catalytic converter or engine.

Why is the MAF sensor such a common cause of P0171 on Nissans?

The MAF sensor on Nissan's 2.5L engines is a known weak point. When it reads wrong, the computer gets bad air flow data and the mixture runs lean, which sets P0171.

How much does it cost to fix P0171 on a Nissan?

MAF cleaning is about $10–$20, and a replacement MAF sensor is $100–$300. Vacuum leak repairs are $10–$100, while a fuel pump issue adds $300–$700.