P0172 on Nissan vehicles
Fuel System Too Rich (Bank 1) — what it means on a Nissan, whether it's safe to drive, and the fixes by model and year.
P0172 on a Nissan means fuel system too rich (bank 1). Most vehicles stay drivable short-term, but diagnose it promptly. The most common cause is leaking or stuck-open fuel injector(s) on bank 1 (typically $150–$1,200). Pick your Nissan model below for its known failure patterns, recalls, and TSBs.
What does P0172 mean on a Nissan?
P0172 is set when the engine control module detects that long-term fuel trim on Bank 1 has been driven beyond approximately −25 % — the ECM is pulling out the maximum amount of fuel it is allowed to remove, and the oxygen sensor still reports a rich mixture. The cause is something delivering excess fuel or restricting air, or a sensor reporting a false rich signal.
P0172 is a standardized OBD-II code, so its definition is the same on every Nissan. What differs by model and engine is which cause is most likely — pick your Nissan model below for a diagnosis tuned to its known failure patterns, recalls, and TSBs.
Is it safe to drive a Nissan with P0172?
In most cases a Nissan stays drivable for short trips with P0172 active, but diagnose and repair it promptly. This is a moderate-severity code — ignoring it can lead to further damage or a failed emissions test. Exact tolerance depends on the model and engine.
What causes P0172 on a Nissan?
| Cause | Likelihood | Estimated repair (USD) |
|---|---|---|
| Leaking or stuck-open fuel injector(s) on Bank 1 — Drip-test individual injectors to find the leaker. | Most common | $150–$1,200 |
| Failed fuel pressure regulator allowing too much fuel | Common | $100–$400 |
| Restricted or dirty air filter / clogged intake | Common | $20–$80 |
| Failed MAF sensor over-reporting airflow | Common | $30–$350 |
| Stuck-closed EVAP purge valve (purge solenoid leaking fuel vapor) | Occasional | $80–$300 |
| Leaking fuel pressure regulator vacuum hose pulling fuel into the intake | Occasional | $20–$150 |
| Failed upstream O2 sensor biased rich | Occasional | $150–$450 |
| Engine oil contaminated with fuel (overdue oil change after rich running) | Rare | $80–$200 |
Repair costs are typical US ranges and vary by Nissan model, model year, and labor rate. A diagnostic trouble code is a symptom, not a guaranteed failed part — confirm the root cause before replacing anything.
P0172 by Nissan model
Select your Nissan model and year for a P0172 diagnosis tuned to that vehicle's failure patterns, recalls, and TSBs.
Nissan Altima
823 NHTSA owner complaints · 7 recalls on record across the years covered below.
Nissan Sentra
484 NHTSA owner complaints · 5 recalls on record across the years covered below.
Nissan Rogue
1,132 NHTSA owner complaints · 13 recalls on record across the years covered below.
Complaint and recall counts are NHTSA totals for the model years covered on this site, not counts specific to P0172.
P0172 on other makes
Other codes on Nissan vehicles
P0172 on a Nissan: frequently asked questions
What does diagnostic trouble code P0172 mean on a Nissan?
P0172 is set when the engine control module detects that long-term fuel trim on Bank 1 has been driven beyond approximately −25 % — the ECM is pulling out the maximum amount of fuel it is allowed to remove, and the oxygen sensor still reports a rich mixture. The cause is something delivering excess fuel or restricting air, or a sensor reporting a false rich signal. P0172 is a standardized OBD-II code, so the definition is the same on every Nissan — which cause is most likely varies by model and engine.
What are the symptoms of P0172 on a Nissan?
Check Engine Light is illuminated. Strong fuel smell from the exhaust. Black smoke from the tailpipe under acceleration. Poor fuel economy (sometimes severely worse — 30 %+ drop). Rough idle and hard starting (flooded condition). Fouled spark plugs from rich-running conditions. Eventual catalytic converter damage (P0420 follows)
What causes P0172 on a Nissan?
Leaking or stuck-open fuel injector(s) on Bank 1 (most-common). Failed fuel pressure regulator allowing too much fuel (common). Restricted or dirty air filter / clogged intake (common). Failed MAF sensor over-reporting airflow (common). Stuck-closed EVAP purge valve (purge solenoid leaking fuel vapor) (occasional). Leaking fuel pressure regulator vacuum hose pulling fuel into the intake (occasional). Failed upstream O2 sensor biased rich (occasional). Engine oil contaminated with fuel (overdue oil change after rich running) (rare)
Is it safe to drive a Nissan with P0172?
In most cases a Nissan stays drivable for short trips with P0172 active, but it should be diagnosed and repaired promptly — this is a moderate-severity code. Ignoring it can lead to further damage or a failed emissions test. Exact tolerance depends on the model and engine.