Worn or fouled spark plug in cylinder 4; Faulty ignition coil or spark plug wire for cylinder 4; Clogged or leaking fuel injector for cylinder 4; Vacuum leak affecting cylinder 4 intake path; Low compression in cylinder 4 due to worn rings, valves, or head gasket; Mechanical valvetrain issue such as a collapsed lifter or worn cam lobe; Wiring or connector problem in the cylinder 4 injector or ignition circuit

DTC codes / P02xx · Fuel and air metering (injector circuits) / P0272

P0272Cylinder 4 Contribution/Balance

Q: What does code P0272 mean?

Cylinder 4 Contribution/Balance. P0272 indicates that the powertrain control module has detected an abnormal contribution from cylinder 4 to engine power, typically by monitoring crankshaft speed fluctuations; a weaker or stronger than expected power stroke from that cylinder sets the code. The computer compares each cylinder's effect on crankshaft acceleration and flags cylinder 4 when its balance value falls outside the acceptable range.

P0272 indicates that the powertrain control module has detected an abnormal contribution from cylinder 4 to engine power, typically by monitoring crankshaft speed fluctuations; a weaker or stronger than expected power stroke from that cylinder sets the code. The computer compares each cylinder's effect on crankshaft acceleration and flags cylinder 4 when its balance value falls outside the acceptable range.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaFuel and air metering (injector circuits)

Symptoms you may notice

Illumination of the check engine light, often with no other noticeable symptoms
A noticeable engine misfire or rough idle, especially when cold
Reduced engine power or sluggish acceleration
Shaking or vibration felt through the steering wheel or seat
Poor fuel economy or an increase in exhaust emissions
In some cases, a flashing check engine light if the misfire is severe

Common causes, most likely first

Worn or fouled spark plug in cylinder 4
Faulty ignition coil or spark plug wire for cylinder 4
Clogged or leaking fuel injector for cylinder 4
Vacuum leak affecting cylinder 4 intake path
Low compression in cylinder 4 due to worn rings, valves, or head gasket
Mechanical valvetrain issue such as a collapsed lifter or worn cam lobe
Wiring or connector problem in the cylinder 4 injector or ignition circuit

How to diagnose and fix it

Perform a visual inspection of cylinder 4 ignition components and wiring for damage or corrosion
Swap the ignition coil and spark plug from cylinder 4 with a known good cylinder to see if the misfire moves
Use a scan tool to check misfire counters and fuel trim data to confirm which cylinder is affected
Run a compression test and a cylinder leak-down test on cylinder 4 to rule out mechanical faults
Test the fuel injector for cylinder 4 with a noid light or injector balance test
Check for vacuum leaks at the intake manifold and cylinder 4 intake runner
If all electrical and fuel checks pass, inspect valvetrain components for wear or damage

What a cylinder 4 balance code really tells you

A P0272 can be set by a faulty injector that is not completely dead but delivers an uneven spray pattern, which often does not trigger a hard misfire code.
Engine vacuum leaks that affect only one intake runner can cause a single-cylinder contribution code without any other cylinders being affected.
A worn spark plug or failing coil may still fire under light load but break down under heavy load, so the code may only appear during acceleration or uphill driving.
Low compression from a failing head gasket can cause a P0272 without any external coolant leaks, so a cylinder leak-down test is essential before replacing ignition parts.
Some vehicles use a contribution balance test that can be skewed by a dirty mass airflow sensor or a failing oxygen sensor, so always check fuel trims before condemning cylinder 4 hardware.

Can I keep driving with P0272?

You can usually drive the vehicle with a P0272 code, but avoid heavy acceleration and long trips until the cause is diagnosed, because a persistent misfire can damage the catalytic converter and waste fuel. If the check engine light flashes, stop driving and have the vehicle towed to a repair shop.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.