A P0301 code displays when your ECM (engine control module) detects a misfire from cylinder one of your engine. Misfire events can happen for many reasons and should be addressed immediately to prevent further damage to your vehicle.

Diagnostic trouble codes (DTCs) are invaluable for identifying engine trouble. An OBD-II code reader can tell you what a code means, but it cannot identify the source of a problem—so identifying the DTC is only half the battle when it comes to vehicle repairs.

To ensure you’re on the right track, the

car insurance

comparison and broker app

Jerry

has compiled this complete guide to the P0301 engine code—what it means, how to fix it, and the total costs involved.

Let Jerry find your price in only 45 seconds

No spam · No long forms · No fees

Find insurance savings

What does the engine code P0301 mean?

Definition: Cylinder 1 misfire detected

A P0301 code happens when a misfire is detected from the first cylinder of your engine.

Engines create power through combustion reactions. Combustion takes place in the cylinders, but when this reaction fails, you’ll experience an

engine misfire

—an abrupt loss of RPMs when your engine fails to produce enough power.

How much will it cost to fix?

Most auto shops will charge from $75 to $150 to diagnose the problem. From there, repair or replacement costs will vary significantly based on the parts needed and the extent of the damage.

What can cause the P0301 engine code?

A P0301 engine code displays when your engine control module (ECM) detects a misfire in cylinder one. Misfires can happen for various reasons, but there are a few common causes.

Problems with the ignition system:

Faulty worn spark plug

Faulty coil pack or plug

Poor spark plug wiring

Issues with fuel delivery:

Faulty

fuel injector

Poor fuel injector circuit wiring

Faulty powertrain control module

Other mechanical issues:

Leaking valve

Worn piston ring or damaged piston

Worn crankshaft lobe

Damaged filter

Leaking head gasket

Multiple cylinders may even misfire due to a single problem—meaning you won’t always need extensive repairs to fix multiple misfire-related codes.

MORE:

Does insurance cover engine failure?

Common symptoms of the P0301 engine code

As soon as the P0301 code appears, your

check engine light will turn on

. Drivers can also expect the following symptoms:

Rough idling

Hard starting

Jerking motion while idle

Jerking motion while moving

Unusually sluggish acceleration

Generally, a car whose engine is misfiring will feel as though it has lost power—so you’ll notice the biggest issues during quick acceleration attempts.

How serious is the P0301 engine code?

A P0301 engine code should never be taken lightly. If left unchecked, cylindrical misfires can cause extensive damage to your engine. You should have the code inspected by a qualified mechanic as soon as possible.

Extreme cylindrical misfiring can also damage the catalytic converter—which will cause the malfunction indicator lamp (MIL) to flash. This component is integral for your engine to operate correctly and can be expensive to replace.

Can I fix the P0301 engine code myself?

Unless you have a mechanical background, you’ll likely be unable to fix this issue on your own. You can, however, inspect your engine to try to narrow down the cause of the issue.

When inspecting your engine cylinder, look for the following signs of damage:

Corroded electrical connections

Bent, broken, or out-of-place components

Fluids leaking from around the cylinder

You may be able to solve the misfire issue by

replacing the spark plugs

on the cylinder. If the problem persists after the new plugs are added, you should visit a mechanic.

MORE:

My check engine light is on—what does it mean?

Finding insurance for your vehicle

A misfiring engine is frustrating—and so is overpaying on the insurance protection your car needs.

Luckily, it’s never been easier to find a lower

car insurance

rate, thanks to

Jerry

. This car super app and licensed broker will gather competitive quotes from 50+ top insurance companies, then send the best options straight to your phone for review.

Just download the app, answer a few questions, and let Jerry work its magic!

Jerry users save an average of $879 per year on car insurance, so it’s a smart way to save money on car expenses in just a few minutes.