P0300 on a 2020 Ford Ecosport

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 2020 Ford Ecosport

Ranked from 390 NHTSA owner complaints filed for this vehicle.

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1
Internal engine damage (spun rod/main bearings, camshaft damage, low compression) from the oil-pump-drive-belt failure — Safety Recall 23S64 / NHTSA 23V905
High severity
This exact vehicle/engine is subject to a documented recall in which the belt-driven oil pump disintegrates, starving the engine of oil pressure; the resulting bearing, camshaft, and ring/valve damage directly produces the low compression and rough-running that sets a random misfire code.
Reported in 14 NHTSA complaints
2
Damaged or fouled fuel injector(s)
Medium severity
A owner-reported fuel-injector problem on this vehicle is consistent with a dead or weak cylinder; a leaking or clogged injector unbalances that cylinder's fuel delivery.
Reported in 1 NHTSA complaint
Parts:fuel injector
3
Worn or fouled spark plugs
Medium severity
Worn electrodes or carbon fouling widen the spark gap until the plug can no longer reliably fire under load, a classic random-misfire cause across all gasoline engines.
Common cause
Parts:spark plugs
4
Failing ignition coil(s)
Medium severity
A cracked or weak coil (or coil-on-plug boot) drops spark energy on one cylinder, especially noticeable under load or when hot.
Common cause
Parts:ignition coil
5
Vacuum leak (intake, PCV, or brake-booster hose)
Medium severity
Unmetered air leaning out one or more cylinders can present as a misfire, especially at idle; check with a smoke test or propane/carb-cleaner spray around fittings.
Common cause
Parts:vacuum hose
6
Carbon-fouled intake valves
Low severity
Direct-injection engines are prone to carbon buildup on the backs of the intake valves, which can disrupt airflow/atomization enough to cause a misfire.
Common cause
7
EGR valve or passage fault
Low severity
A stuck-open EGR valve or clogged passage can dump too much exhaust gas into a cylinder at the wrong time, causing it to misfire.
Common cause
Parts:EGR valve

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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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Matching symptoms

Car Runs Rough Flashing Check Engine Light