P0300 on a 2015 Dodge Dart

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 2015 Dodge Dart

Ranked from 510 NHTSA owner complaints filed for this vehicle.

Sort by:

1
Low compression from oil/ring wear (2.4L Tigershark oil-consumption issue)
High severity
Multiple owners of this exact engine report heavy oil consumption, blow-by, and repeated stalling/rough-running tied to a well-documented factory oil-control/ring problem, which drops cylinder compression enough to cause misfires.
Reported in 5 NHTSA complaints
2
Faulty PCM/ECM commanding incorrect ignition or fuel timing
High severity
One owner's car began misfiring and required a full ECM rebuild before it ran correctly, pointing to control-module failure as a real (if less common) root cause on this platform.
Reported in 1 NHTSA complaint
3
Worn or fouled spark plugs
Low severity
Baseline wear item, more likely to show symptoms early on an engine already prone to oil consumption/fouling.
Common cause
Parts:spark plugs
4
Failing ignition coil
Medium severity
A weakening coil drops spark energy under load, producing an intermittent single- or multi-cylinder misfire.
Common cause
Parts:ignition coil
5
Clogged or leaking fuel injector
Medium severity
Uneven fuel delivery to one cylinder produces a repeating misfire on that cylinder.
Common cause
Parts:fuel injector
6
Vacuum or intake leak
Medium severity
Unmetered air leans out the mixture enough to cause a misfire, especially at idle.
Common cause
7
EGR valve fault
Low severity
A stuck-open EGR valve dilutes the intake charge and disrupts combustion at idle/low load.
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