P0300 on a 2013 Nissan Sentra
P0300 is a generic OBD2 powertrain code for random or multiple cylinder misfire. Unlike P0301 through P0308, it does not point to one specific cylinder, so the cause can be ignition, fuel, air, sensor, or mechanical.
Not your vehicle? See general P0300 info.
Most common causes on the 2013 Nissan Sentra
Ranked from 638 NHTSA owner complaints filed for this vehicle.
- 1
Mass Air Flow (MAF) sensor failure or dirty
Medium severityAn inaccurate MAF sensor reading causes the ECM to calculate the wrong air/fuel mixture, leading to random misfires. Often accompanied by P0101.
Reported in 2 NHTSA complaints - 2
Faulty spark plugs
Medium severityWorn or fouled spark plugs are a primary cause of engine misfires. Look for worn electrodes, carbon buildup, or incorrect gap.
Common cause - 3
Faulty ignition coils
Medium severityA failing ignition coil will not provide the necessary voltage to the spark plug, causing a misfire. Confirm by swapping coils between cylinders to see if the misfire moves.
Common cause - 4
Vacuum leak
Medium severityUnmetered air entering the intake manifold leans out the air/fuel mixture, causing random misfires. Check for cracked hoses, intake manifold gasket leaks, or a loose PCV valve.
Common cause - 5
Low fuel pressure / Failing fuel pump
High severityInadequate fuel delivery causes a lean condition leading to random misfires across multiple cylinders. Confirm with a fuel pressure gauge.
Common cause - 6
Clogged or faulty fuel injectors
Medium severityRestricted fuel flow or a mechanically failing injector prevents proper combustion. Look for poor spray patterns or electrical resistance out of spec.
Common cause - 7
EGR valve stuck open
Medium severityExhaust gases entering the intake at the wrong time dilute the air/fuel mixture, causing misfires and rough idling.
Common cause - 8
Engine mechanical issues (low compression)
High severityWorn piston rings, burnt valves, or a blown head gasket prevent proper compression, leading to misfires. Confirm with a compression or leak-down test.
Common cause
These causes are aggregated from NHTSA owner complaints and general repair knowledge — this is not a diagnosis. P0300 on your car still needs shop confirmation before any repair.
Common symptoms
- Flashing or steady check engine light
- Rough idle
- Shaking under acceleration
- Loss of power
- Fuel smell from exhaust
What to check before replacing parts
Scan for cylinder-specific misfire codes
Look for: A companion P0301–P0308 pins the misfire to one cylinder — start there. P0300 with no cylinder code points at something hitting several at once: fuel pressure, a large vacuum leak, or timing.
Inspect the spark plugs and coils
Look for: Pull the plugs: black/sooty = rich, oily = oil intrusion, white/blistered = lean or overheating, cracked porcelain or an out-of-spec gap = replace. Then swap a coil to another cylinder — if a cylinder-specific code follows the coil, the coil is bad.
Check fuel trims for a vacuum leak
Look for: High positive short- and long-term trims (worst at idle, improving as RPM rises) mean unmetered air is getting in. Smoke-test the intake and listen for hissing.
Verify fuel pressure
Look for: Compare running/cranking pressure to the vehicle spec. Low or dropping pressure starves multiple cylinders and reads as a random misfire — suspect the pump, filter, or regulator.
Compression / leak-down test if ignition and fuel check out
Look for: A cylinder 15%+ below the others, or leak-down hissing from the intake (intake valve), exhaust (exhaust valve), or oil filler (rings), means the misfire is mechanical — not a swap-in part.
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