P0301 on a Chevrolet

Researched from the OBD-II standards and published manufacturer specifications

Quick answer

On GM LS-family V8 engines, a cylinder 1-specific misfire is commonly traced to that cylinder's individual ignition coil or, on AFM/DOD-equipped engines, to a lifter specific to that cylinder position.

Severity 3 of 4. Short trips only.

Fix now · Short trips only

P0301 on a Chevrolet, at a glance
CodeP0301
Standard nameCylinder 1 Misfire Detected
MakeChevrolet
SeverityFix now (3 of 4)
Safe to driveShort trips only
Tool neededScanner with live data
Reads P0301: live data and freeze frame

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Adds live sensor streams and freeze frame, which is what turns a code into a diagnosis rather than a guess.

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Coverage varies by tool and by model year, so check a specific tool against a specific vehicle before buying.

What is different about P0301 on a Chevrolet?

Because GM LS-family V8 engines use individual coils and, on many models, individual deactivation lifters per cylinder, a code isolated to cylinder 1 points diagnosis directly at that cylinder's specific hardware.

Patterns documented on Chevrolet vehicles

Cylinder-specific coil failure: The coil-near-plug ignition design on GM LS-family V8 engines means a single failing coil produces a code isolated to that exact cylinder, making a coil swap between cylinders a documented and effective diagnostic step.

AFM/DOD lifter failure specific to cylinder 1: On engines equipped with Active Fuel Management or Displacement on Demand, a documented lifter failure specific to the cylinder 1 position can produce a P0301 code distinct from an ignition-related cause.

What to check first on a Chevrolet

The order below narrows the generic P0301 list down to what is worth checking first on this make. It is a starting order, not a diagnosis: patterns are generation specific and a vehicle outside those generations may have none of them.

Check in this order

  • Swap the cylinder 1 ignition coil with another cylinder's coil to see if the misfire follows the coil
  • Check for lifter-related valvetrain noise specific to cylinder 1 on AFM/DOD-equipped engines
  • Inspect the cylinder 1 spark plug for wear or fouling
  • Check for a vacuum leak local to that cylinder's intake runner

The generic picture behind P0301

The computer counts tiny fluctuations in crankshaft speed between firing events and attributes each misfire to the cylinder whose firing position lines up with the disturbance. This code sets when that pattern repeatedly points to cylinder 1 specifically, rather than being spread across the engine. A single cylinder misfire almost always traces back to something local to that cylinder, such as its plug, coil or injector.

Everything on the main P0301 page still applies here. This page narrows the cause list to the patterns documented on Chevrolet vehicles, it does not replace the underlying definition.

The generic version of this code

Tools that can diagnose P0301

Adds live sensor streams and freeze frame, which is what turns a code into a diagnosis rather than a guess.

Common questions

How do I tell if a P0301 is the coil or the lifter on a GM V8?

Swapping the cylinder 1 ignition coil with a coil from another cylinder and rescanning is a documented, straightforward way to check: if the misfire code moves to the other cylinder, the coil was the cause. If it stays on cylinder 1, a lifter or other mechanical cause specific to that cylinder is more likely on AFM/DOD-equipped engines.

Which cylinder is cylinder 1 on a GM V8?

Cylinder numbering varies by specific engine family and configuration, so check a cylinder numbering diagram for your exact GM V8 engine rather than assuming, since it is not universal across every GM V8 layout.

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