P0300 on Infiniti
Random/Multiple Cylinder Misfire Detected
P0300 on Infiniti vehicles indicates random/multiple cylinder misfire detected. Au7o has documented this code across 2 Infiniti models — most commonly on QX55, QX80. P0300 means the engine computer detected misfires occurring randomly or across multiple cylinders rather than in one specific cylinder. A misfire is when a cylinder fails to ignite its fuel-air mixture properly, which the computer senses through small fluctuations in crankshaft speed. Because it's not isolated to one cylinder, the cause is usually something that affects the whole engine — like fuel, air, or ignition system problems — rather than a single coil or plug. Persistent or heavy misfiring wastes fuel, runs rough, and can damage the catalytic converter, which is why a flashing check engine light should be taken seriously. Typical repair costs on Infiniti range from $2,000 to $14,000, depending on the specific model and root cause.
Common Causes of P0300
- •Worn or fouled spark plugs (across cylinders)
- •Vacuum or intake air leak
- •Weak fuel pump, clogged fuel filter, or low fuel pressure
- •Failing ignition coils or worn spark plug wires
- •Dirty or faulty mass airflow (MAF) sensor
- •Clogged or dirty fuel injectors
- •Faulty crankshaft/camshaft position sensor
- •Low compression or EGR/PCV system faults
P0300 on Infiniti by Model
Infiniti QX55(1 issue)
- VC-Turbo Engine Main/Link Bearing Failure (Safety Recall)2022-2024
Nissan issued a large 2026 recall covering VC-Turbo four-cylinder vehicles including the Infiniti QX55, QX50 and Altima. Under certain operating conditions the engine can experience high oil temperatures that degrade lubrication of the crankshaft main bearing and the A-, C- and L-link bearings of the variable-compression mechanism. In the worst case a bearing seizes or a failed bearing breaches the engine block, causing catastrophic engine failure. This is a distinct defect from the previously documented oil-consumption issue. Nissan also announced a VC-Turbo warranty extension. Symptoms often precede failure and out-of-warranty engine replacements have run five figures.
Infiniti QX80(1 issue)
- VK56VD Timing Chain Stretch2011-2017
The 5.6L VK56VD engine can develop timing chain stretch, particularly when oil changes are neglected. The primary and secondary timing chains elongate over time, causing rough idle, reduced power, and potential engine damage if not addressed.
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View P0300 across all makes →Frequently Asked Questions
What does P0300 mean on Infiniti?▼
P0300 stands for "Random/Multiple Cylinder Misfire Detected." P0300 means the engine computer detected misfires occurring randomly or across multiple cylinders rather than in one specific cylinder. A misfire is when a cylinder fails to ignite its fuel-air mixture properly, which the computer senses through small fluctuations in crankshaft speed. Because it's not isolated to one cylinder, the cause is usually something that affects the whole engine — like fuel, air, or ignition system problems — rather than a single coil or plug. Persistent or heavy misfiring wastes fuel, runs rough, and can damage the catalytic converter, which is why a flashing check engine light should be taken seriously. On Infiniti specifically, this code is documented across 2 models.
What causes P0300 on Infiniti vehicles?▼
Common causes on Infiniti: Worn or fouled spark plugs (across cylinders), Vacuum or intake air leak, Weak fuel pump, clogged fuel filter, or low fuel pressure, Failing ignition coils or worn spark plug wires, Dirty or faulty mass airflow (MAF) sensor. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0300 on a Infiniti?▼
Repair costs on Infiniti range from $2,000 to $14,000, depending on the specific model and root cause.
Which Infiniti models have P0300 documented?▼
Au7o has documented P0300 on 2 Infiniti models: QX55, QX80.