P0300 on a 2019 Chevrolet Equinox
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 2019 Chevrolet Equinox
Ranked from 292 NHTSA owner complaints filed for this vehicle.
- 1
Vacuum Pump Failure/Explosion
High severityThe mechanical vacuum pump seizes and shatters, sending metal debris into the engine, damaging the camshaft and timing components, and causing a loss of brake assist.
Reported in 14 NHTSA complaints - 2
Charge Air Cooler (CAC) Tube Disconnection
Medium severityThe charge air cooler tube or intake hose disconnects from the throttle body, causing a loss of boost, reduced engine power, and stalling.
Reported in 4 NHTSA complaints - 3
Timing Chain Failure
High severityThe timing chain stretches or fails, often secondary to vacuum pump debris or oil starvation, leading to engine damage and misfires.
Reported in 3 NHTSA complaints - 4
Turbocharger Failure
High severityThe turbocharger fails, leading to underboost conditions (P0299), reduced engine power, and potential misfires.
Reported in 2 NHTSA complaints - 5
Faulty Spark Plugs
Low severityWorn or fouled spark plugs fail to ignite the air/fuel mixture properly, causing random misfires.
Common cause - 6
Faulty Ignition Coils
Medium severityWeak or failing ignition coils cannot provide sufficient voltage to the spark plugs, leading to misfires across multiple cylinders.
Common cause - 7
Vacuum Leaks
Medium severityUnmetered air enters the intake manifold, causing a lean condition that results in random misfires.
Common cause - 8
Low Fuel Pressure
Medium severityA failing fuel pump or clogged fuel filter restricts fuel delivery, causing a lean condition and misfires.
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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