P0300 on a 2016 Ford Explorer
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 2016 Ford Explorer
Ranked from 2,432 NHTSA owner complaints filed for this vehicle.
- 1
Coolant intrusion into a cylinder from a cracked cylinder head/failed head gasket
High severityTwo owners independently report coolant leaking into the cylinders/cylinder walls, causing white smoke, overheating and stranding - a well-documented failure mode on this engine that destroys compression/misfires the affected cylinder.
Reported in 2 NHTSA complaints - 2
Ignition coil failure
High severityAn owner's intermittent power-loss/jerk event was ultimately addressed by replacing all ignition coils after plugs alone didn't fix it.
Reported in 1 NHTSA complaintParts:ignition coil - 3
Worn spark plugs
Medium severityThe same recurring power-loss complaint had spark plugs replaced as part of the failed repair attempts.
Reported in 1 NHTSA complaintParts:spark plug - 4
Timing chain or cam phaser wear (documented EcoBoost issue)
High severityAn owner had the timing chain fail twice (with resulting piston/rod damage), a widely reported issue on these engines that disrupts valve timing and causes rough running/misfire.
Reported in 1 NHTSA complaint - 5
Vacuum or intake gasket leak
Medium severityA cracked valve/intake gasket was found on one power-loss complaint, consistent with an unmetered air leak that can trigger misfire.
Reported in 1 NHTSA complaint - 6
Clogged or leaking fuel injector
Medium severityA fouled or dripping injector delivers an incorrect fuel charge to a cylinder, producing a misfire.
Common causeParts:fuel injector - 7
Low compression from worn piston rings/valves
Medium severityGeneral mechanical wear reduces cylinder sealing and combustion efficiency, producing a misfire under load.
Common cause
Part links go to Amazon search results for this vehicle. As an Amazon Associate, WrenchConnect earns from qualifying purchases — always confirm fitment for your exact trim and engine before ordering.
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.
Rather have a pro handle it? Find a vetted local mechanic.