P0300 on a 2016 GMC Yukon

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 GMC Yukon

Ranked from 265 NHTSA owner complaints filed for this vehicle.

Sort by:

1
Active Fuel Management (AFM/DOD) lifter and pushrod failure
High severity
By far the dominant pattern in this batch: repeated bent pushrods, collapsed/failed lifters, and camshaft lobe wear on the 6.2L, explicitly tied by owners and shops to the AFM cylinder-deactivation system, producing a misfire on the affected cylinder(s).
Reported in 10 NHTSA complaints
Parts:valve lifter push rod camshaft
2
Failing or leaking high-pressure direct-injection fuel injector
Medium severity
Owners report rough running/stuttering with a gasoline smell tied to the injector/fuel-pump system, and a separate case of coolant found intruding at an injector -- both point to injector or injector-seal failure disrupting combustion.
Reported in 2 NHTSA complaints
Parts:fuel injector high-pressure fuel pump
3
Worn or fouled spark plugs
Low severity
Plugs beyond their service interval lose spark energy and misfire under load; inspect gap and fouling pattern.
Common cause
Parts:spark plugs
4
Failing ignition coil
Medium severity
A weak or cracked coil drops spark to one cylinder, typically showing as a repeating single-cylinder misfire.
Common cause
Parts:ignition coil
5
Vacuum leak (intake manifold, hoses)
Medium severity
Unmetered air leaning out a cylinder can present as a misfire, particularly noticeable at idle; smoke-test the intake.
Common cause
6
EGR valve fault
Low severity
A stuck-open EGR valve over-dilutes the intake charge and can cause a rough idle or misfire; test EGR flow.
Common cause
Parts:EGR valve
7
Carbon-fouled intake valves
Low severity
Direct-injection engines like this one lack fuel washing the back of the intake valves, so carbon buildup there is common and can cause a lean pocket/misfire on affected cylinders.
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.

Matching symptoms

Car Runs Rough Flashing Check Engine Light