P0300 on a 2017 Kia Sorento

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 2017 Kia Sorento

Ranked from 788 NHTSA owner complaints filed for this vehicle.

Sort by:

1
Low compression / cylinder fouling from the documented Lambda/Theta oil-consumption defect
High severity
Numerous owners report heavy oil consumption and worn internals (some diagnosed as rod bearing failure) on this engine family; oil pulled into the cylinders fouls plugs and lowers compression, producing misfire.
Reported in 6 NHTSA complaints
2
Variable valve timing (E-CVVT) actuator or cam-timing correlation fault
Medium severity
One vehicle logged a Bank 2 cam/crank correlation code traced to loose cam pins, and another had an E-CVVT motor failure causing surging and a limp-home mode; incorrect valve timing from either fault directly produces misfire-like symptoms.
Reported in 2 NHTSA complaints
Parts:variable valve timing actuator timing chain
3
Worn or fouled spark plugs
Medium severity
Widened gaps or fouling (often accelerated by the oil-consumption issue on this engine) reduce spark energy; check gap and electrode condition.
Common cause
Parts:spark plugs
4
Failing ignition coils
Medium severity
A weak or arcing coil produces a repeatable single- or multi-cylinder misfire; swap-test between cylinders to confirm.
Common cause
Parts:ignition coil
5
Clogged or leaking fuel injectors
Medium severity
Deposit buildup or a leaking injector disrupts the air/fuel ratio on an individual cylinder; injector balance test isolates it.
Common cause
Parts:fuel injector
6
Vacuum/intake leak
Medium severity
Unmetered air entering after the MAF leans out one or more cylinders enough to misfire under load or idle.
Common cause
7
Carbon-fouled intake valves
Low severity
Direct-injection engines accumulate carbon on the backs of the intake valves over time, disrupting airflow/atomization and contributing to misfire.
Common cause
8
EGR valve stuck open
Low severity
Excess exhaust gas recirculated at idle/low speed dilutes the charge enough to cause a rough idle and misfire.
Common cause
Parts:egr valve

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.

Matching symptoms

Car Runs Rough Flashing Check Engine Light