P0300 Code: Safe to Drive? Causes, Costs and Who Pays

P0300 is the code the OBD-II system sets when the engine counts misfires it can't pin on one cylinder, a random or multiple cylinder misfire. Scanners also call it a P0300 error code, and you meet it as a check engine light, steady or flashing, with or without shaking, a rough idle or lost power.

The usual answer is a set of plugs and coils, and sometimes that's right. But the carmakers' own P0300 documents point at shared causes: coolant reaching the cylinders on Ford's 1.5-liter engine, lifters coming apart on some GM V8s, and a head gasket on a long list of Hondas.

A flashing light, lost power, a burning smell or overheating means you stop driving first. On a misfire, the cheapest checks are the ones that rule out the most expensive parts.

What does a P0300 code mean?

P0300 means the computer counted misfires spread over more than one cylinder, or moving around too much to name one. In plain terms, when the misfires aren't mostly in one cylinder, the car stores P0300 instead of a cylinder code.

A single bad coil can earn its cylinder its own code instead, such as P0301 for cylinder 1. The box at the end of this page lists each of those.

A P0300 on the scan tool

Can you drive with a P0300 code?

Yes, with a steady light, gently and to a shop, but if it flashes, the engine loses power, you smell burning or it overheats, stop as soon as it's safe and have it towed. The regulation splits misfire into two tiers, and only the one heavy enough to damage the catalytic converter makes the light blink, once a second.

A steady light means misfire bad enough to break the emission limit, judged over 1,000 revolutions and confirmed on a later drive. Here's what each light means on a P0300 code and what the owner's manuals tell you to do:

• Steady light. Over the emission limit, not on fire. Drive gently, avoid hard acceleration and get it checked soon.
• Flashing light. Enough misfire to overheat the catalytic converter. Ease off and stop as soon as it's safe, then have it towed.
• Flashing with a burning smell, smoke or low coolant. Stop in a safe place away from anything that burns and let the engine cool, ten minutes or more by Honda's manual.

Heat is the reason to stop, because a flashing light means unburned fuel is overheating the converter. Our flashing check engine light page explains how that happens.

What are the symptoms of a P0300 code?

A misfiring engine runs on fewer cylinders than it was built for, and you feel the missing ones. The P0300 symptoms owners describe most are lost power, shaking or a rough idle, stalling, a flashing light and a car that had to be towed.

Lost power and shaking at a stop lead the signs owners name, and a flashing light is the one to act on. A misfire also wastes fuel, and the unburned part of it goes straight into the exhaust, which is where the trouble with a flashing light begins.

What causes a P0300 code?

P0300 sets when something stops several cylinders from burning their fuel cleanly: worn ignition parts, coolant in the cylinders, damaged valve parts, or a fuel and air problem. These are the six causes to check, worn parts first because they come up on every engine, and carmaker documents back the coil, coolant, lifter and software causes.

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1. Worn spark plugs or coils across the set

Every cylinder has a spark plug, and many engines a coil on top of each plug that makes the spark. Plugs wear on a schedule, so a set at the end of its life can misfire in several cylinders at once, which is a P0300 rather than a one-cylinder code.

GM found water in the coil connectors behind P0300 with the coil circuit codes on one of its trucks, and its own test is to swap the coil to a good cylinder. Check when your plugs were last changed against the owner's manual.

2. Coolant in the cylinders

Coolant that leaks into a cylinder won't burn, so the cylinder misfires, and the leak can reach more than one. You may see the coolant level drop with no puddle under the car, and sometimes white smoke from the exhaust.

Ford's program for its 1.5-liter EcoBoost in the Escape and Fusion names exactly this, and Honda's head gasket extension lists coolant loss with P0300 through P0304. Mention a falling coolant level to the shop first. The P0301 page covers the Ford engines in detail.

3. A collapsed valve lifter

Lifters are small parts that pass the camshaft's push to the valves. When one collapses or comes apart, its cylinder stops breathing properly and misfires.

GM found this on some of its V8 trucks and SUVs. Its fix replaces the lifters and guides, so a misfire on one of those trucks belongs at a dealer first.

4. A fuel or air problem

Every cylinder shares the same fuel supply and the same incoming air, so a fault in either reaches all of them at once. Low fuel pressure, a vacuum leak that lets in air the sensor never measured, or a mass air flow sensor reading wrong can each thin the mixture until several cylinders misfire.

A lean code stored beside P0300 is the clue here, and the P0171 page explains what it measures. A mass air flow sensor reading wrong often sets its own code, such as P0101, though not always.

5. Engine software

The engine computer decides when a misfire is real, and makers sometimes fix a misfire with new engine software rather than a part. The repair is a software update at the dealer, with no part changed.

One Ram bulletin, for example, updates the engine computer for a light with P0300 and a rough cold start, blaming the software. Ask the dealer to check your VIN, the 17-character vehicle ID, for an update before parts are ordered.

6. A single-cylinder fault that spread

One cylinder misfiring hard can unsettle the count enough that the computer stores P0300 alongside that cylinder's own code. P0300 beside P0303, for example, means a general misfire with cylinder 3 pinned inside it, so start with that cylinder, the strongest lead you have.

How do you fix a P0300 code?

You fix it by ruling out the free and covered causes before buying parts. The codes stored beside P0300 say where to start, and here's what each one points at, from the carmakers' documents and the code rule:

• P0301 to P0308 beside it. A named cylinder inside a general misfire. Start there.
• P0316 beside it. The misfire began right after startup. Ford's coolant program lists it with P0300.
• P1285 or P1299 beside it, on a Ford. Two Ford codes that its 1.5-liter coolant program lists with P0300.
• P0351 to P0358 beside it. A coil circuit fault. GM checked the coil connectors for water when they set with P0300.
• P0171 or P0174 beside it. A lean mixture across a bank, one side of a V engine, which points at fuel or unmeasured air.

When a code names a cylinder, a coil swap costs nothing. Here's how the coil swap test reads:

• Swap the coil. Move that coil to another cylinder, write the codes down, clear them and drive gently, with a steady light only.
• The misfire follows the coil. The coil is bad.
• The misfire stays put. Look at the plug, the injector or the cylinder itself.

Note which coil went where, and don't drive a badly misfiring engine longer than it takes. Checking the coolant level cold and asking the shop for a compression or leak-down test, which shows how well each cylinder holds pressure, rule out the expensive causes before parts are ordered.

What are the steps to fix a P0300 code?

To fix a P0300 code, work through the 6 steps below, in order:

1. Watch the light. A flashing light means stop as soon as it's safe, as the safety section explains.
2. Read and save every code. Write down P0300 and anything beside it, because a cylinder code, P0316, P1299 or a lean code each points somewhere different.
3. Check the coolant level cold. A level that keeps dropping with no leak outside points at coolant in a cylinder, the Ford and Honda cases above.
4. Run the VIN. A free VIN check lists the recall campaigns for your model year first, and a dealer can check Honda's extension, Ford's program and software updates by VIN.
5. Check when the plugs were changed. If they're due by your owner's manual, a set of plugs is the cheapest repair, and a coil swap tests a named cylinder for free.
6. Ask for a compression or leak-down test before big parts. It shows whether a cylinder is sealing, and a cooling system pressure test or a camera look into the cylinder is what points at a head gasket.

Step 3 can miss a slow leak, and step 4 won't show an extension your dealer hasn't searched for, so ask the dealer to check Honda's bulletin 26-003 family by name. If a shop quotes a head gasket or an engine with no test result behind it, ask which test showed it, and reading a repair estimate shows what else to ask.

How much does it cost to fix a P0300 code?

Usually a set of plugs or a coil, parts and labor, and the costly repairs are the shared causes carmakers have paid for on some cars. One coil on a 2025 Silverado 1500 5.3L runs $88–$242 at an independent shop, and six plugs on a 2021 Grand Cherokee 3.6L run $330–$660, both parts and labor.

A head gasket is the other end of the scale, at $1,010–$1,690 on a 2025 Civic 2.0, parts and labor, independent shop to dealer. Honda's extension covers that 2025 Civic 2.0 and many other Hondas, so check whether it covers yours before you pay.

Who pays for a P0300 repair?

You pay unless a carmaker program covers your car, and of the three makers here only Honda and Ford printed one. Honda's head gasket extension is the widest, so run your VIN through our free VIN checker and a Honda or Acura dealer before you pay anyone for a head gasket.

Ford's 1.5-liter program paid for a new short block, the engine's lower half, for 7 years or 84,000 miles from the warranty start, and the 7-year window has closed on most 2017–2019 cars. GM's lifter bulletin is a repair procedure rather than an extension, so whether GM pays depends on your powertrain warranty.

Will a P0300 code go away on its own?

The light can go out, but the cause behind it is often still there. For misfire, the rule lets the light go out after three trips in a row under similar driving conditions without misfire over the limit, and a misfire that comes back lights it again.

The stored code stays longer, and the computer erases it only after many fault-free drives. Clearing it with a scan tool removes the record, not the cause.

How is P0300 different from P0301 through P0308?

P0300 names no cylinder, and P0301 through P0308 each name one by its number. So the search runs the other way: a numbered code points at a part on one cylinder, and P0300 at something the cylinders share.

The number belongs to the engine's own scheme, not to anything you can count from the front of the car. Honda's 3.5-liter V6 puts cylinders 1 to 3 on the rear head. Chrysler's 3.6-liter tests cylinders 2, 4 and 6 before it replaces the left head, so look up your engine's numbering before you pull a coil.

What does P0300-00 mean?

A suffix such as -00 in P0300-00 doesn't make it a different code. Chrysler's bulletin 18-004-24 lists P0300-00 as the same multiple cylinder misfire.

P0300 means the same random or multiple misfire on every make, a Chevy Silverado, a Camry and a Ram alike. So read the suffix as part of the same code and follow the steps on this page.

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Common questions

Asked most often

How do you fix P0300 on a Chevy Silverado 1500?

Start with the coils and plugs: GM's note for the 2014 Silverado tells technicians to look for water in the coil connectors and to swap the coil to test it. On trucks and SUVs built September 1, 2020 to March 31, 2021, a misfire points at GM's lifter bulletin, 23-NA-043, which replaces the lifters and guides.

Should you clear a P0300 code before the shop sees it?

No. Write every code down first, because clearing it with a scan tool removes the record, not the cause, and a misfire that comes back lights it again.

What percentage of misfires sets the code?

A maker may store a cylinder code when more than 90% of the misfires are in one cylinder, and must store P0300 when two or more cylinders each carry more than 10%, counted over blocks of 200 and 1,000 crankshaft turns. Beyond that each maker sets its own limits, with floors of 5% for catalyst damage and 1% for emissions, and the 4% quoted in many places isn't in the rule.

Is P0351 the same problem as P0301?

Not quite. P0351 reports cylinder 1's coil circuit, which can come with a P0301 misfire, and the same swap test applies.

Prices are ranges compiled in October 2026 for the US market and vary by region, engine and shop rate. Prices from $10 up are rounded to the nearest dollar, so $14.13 reads as $14 and $14.52 as $15. Below $10 they're exact. This article is general information, not advice about your specific vehicle. See the disclaimer.