P0172 on RAM
System Too Rich (Bank 1)
P0172 on RAM vehicles indicates system too rich (bank 1). Au7o has documented this code across 1 RAM model — most commonly on 1500. P0172 means the engine computer has determined the air/fuel mixture on bank 1 is too rich — there is too much fuel relative to air. The PCM watches the oxygen sensors and fuel trims; when it must repeatedly cut back fuel to compensate for an over-rich condition and hits its correction limit, it sets this code. Bank 1 is the side of the engine containing cylinder number one. You may notice poor fuel economy, rough idle, a sulfur/rotten-egg smell, black exhaust smoke, or fouled spark plugs. Typical repair costs on RAM range from $150 to $600, depending on the specific model and root cause.
Common Causes of P0172
- •Dirty or faulty mass airflow (MAF) sensor
- •Leaking or stuck fuel injector
- •High fuel pressure (faulty regulator)
- •Faulty oxygen sensor giving skewed readings
- •Clogged or dirty air filter
- •Leaking evaporative purge valve adding fuel vapor
- •Engine coolant temperature sensor reading too cold
- •Worn spark plugs causing inefficient combustion
P0172 on RAM by Model
RAM 1500(1 issue)
- 5.2L/5.9L Magnum Intake Manifold Plenum Pan Gasket Failure (Oil Burning, Misfire, Cat Damage)1994-2001
On Magnum-engine Rams the intake manifold has a stamped-steel plenum pan sealed to the aluminum manifold by a one-piece gasket. Because steel and aluminum expand at different rates, the gasket tears over time and lets engine oil from the lifter valley get drawn into the intake plenum and burned. Virtually every high-mileage 3.9/5.2/5.9 Magnum develops this. Burned oil fouls the oxygen sensors, causes detonation (pinging), and can destroy the catalytic converters if ignored.
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View P0172 across all makes →Frequently Asked Questions
What does P0172 mean on RAM?▼
P0172 stands for "System Too Rich (Bank 1)." P0172 means the engine computer has determined the air/fuel mixture on bank 1 is too rich — there is too much fuel relative to air. The PCM watches the oxygen sensors and fuel trims; when it must repeatedly cut back fuel to compensate for an over-rich condition and hits its correction limit, it sets this code. Bank 1 is the side of the engine containing cylinder number one. You may notice poor fuel economy, rough idle, a sulfur/rotten-egg smell, black exhaust smoke, or fouled spark plugs. On RAM specifically, this code is documented across 1 model.
What causes P0172 on RAM vehicles?▼
Common causes on RAM: Dirty or faulty mass airflow (MAF) sensor, Leaking or stuck fuel injector, High fuel pressure (faulty regulator), Faulty oxygen sensor giving skewed readings, Clogged or dirty air filter. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0172 on a RAM?▼
Repair costs on RAM range from $150 to $600, depending on the specific model and root cause.
Which RAM models have P0172 documented?▼
Au7o has documented P0172 on 1 RAM model: 1500.