P0305 Code? Check the Coolant Before You Buy a Coil

A P0305 code is the OBD-II diagnostic trouble code (DTC) for cylinder 5 misfire detected: the engine computer saw the fuel and air in cylinder 5 fail to burn on too many strokes. It turns on the check engine light, which stays steady or flashes while the engine shakes.

Scan tools also print it as P030500, the form Toyota uses in its bulletins, and owners type it as PO305 with a letter O. A four-cylinder engine has no cylinder 5, so this code comes from a V6, a V8, or an inline five or six.

This page covers what the code measures, where cylinder 5 sits, how to split a coil fault from a cylinder fault, when to stop driving, and what the parts cost on an F-150, a Silverado and a Ram 1500. It's built from the carmakers' bulletins, two owner's manuals and the 74 federal complaints that name P0305.

What does P0305 mean?

P0305 means cylinder 5 alone missed often enough to push emissions up, or at a higher rate, to put the catalytic converter at risk. The counting rule behind every misfire code is explained on the P0300 page.

Seen alone, it says the computer could pin the misfires on one cylinder. Stored next to P0300, the random misfire code, it means more than one cylinder may be missing, and 22 of the 74 complaints list the two together.

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Can you drive with a P0305 code?

Yes, if the light is steady: drive gently, and only until a shop can see it. If it flashes, slow down and pull over when it's safe, and if the coolant keeps dropping, park it until it's checked.

A steady light gives you time to book a shop. We'd stop driving in three cases:

• The light flashes. The flashing check engine light page explains the blink on any code, and bad catalytic converter symptoms shows what a long misfire does further down the exhaust.
• The coolant keeps dropping. Coolant leaking into a cylinder can end in an overheated engine, and 12 of the 15 Pacifica complaints mention coolant or the head gasket.
• It shakes hard or stalls. Owners describe losing power at highway speed, one while merging into traffic.

What the manuals say 2 manuals

• 2012 Ford F-150, page 13. A blinking light means a misfire that could damage the catalytic converter: drive in a moderate fashion, avoiding heavy acceleration and deceleration, and have it serviced immediately.
• 2020 Chevrolet Silverado, pages 135–136. While it flashes, reduce speed and avoid hard acceleration and uphill grades; if it keeps flashing, park, switch off and wait at least 10 seconds before restarting.

The manuals' full wording, side by side, is on the P0300 page. That page also covers why the lamp flashes for some misfires and stays steady for others.

Will a P0305 code go away on its own?

The light may go out by itself, but that doesn't mean cylinder 5 is fixed. California's OBD-II rule lets the light go out after three trips in a row under similar driving conditions with no misfire over the limit, and a miss that returns lights it again.

The stored code stays longer: the rule lets the computer erase it after 40 warm-up cycles without the fault, each a drive that warms the coolant by at least 40°F to at least 160°F. Clearing it with a scan tool erases the record, not the cause.

What causes a cylinder 5 misfire?

Something that only cylinder 5 has, its plug, coil or injector, or a fault inside the cylinder: coolant, worn valvetrain parts or low compression. The carmakers' bulletins add software, and the table below sets out each cause's clue and its next test.

P0305 by itself proves none of these, and a second code stored with it can change which cause comes first. Here's each cause with the test that comes next:

Here's what owners name in their complaints, which isn't a diagnosis:

Each cause gets its own section below, in the table's order. Plug, coil and injector come first, then coolant, the valvetrain, software and the wiring and fuel supply.

1. Spark plug

The plug fires the mixture in cylinder 5, and NGK, a plug maker, says the voltage a plug needs to fire rises with its gap. NGK also lists oil use from worn piston rings or cylinder walls among the causes of a fouled plug.

Chrysler has also fixed plugs in batches, replacing cracked plugs on its 3.6L V6 and having dealers re-gap a supercharged V8's. Both bulletins, with the years they cover, are in the list below.

Chrysler's plug bulletins 2 docs

• 2020–21 Pacifica, Durango, Grand Cherokee; 2021 Wrangler, Gladiator, Ram 1500, 3.6L. Plugs with an internal crack, in listed build windows; all six are replaced and the repair is reimbursable under warranty. Bulletin 09-013-20 Rev. A.
• 2023 Dodge Challenger 6.2L supercharged. Plug gaps out of spec; each of the sixteen plugs is measured and re-gapped, 1.7 hours. Bulletin 09-016-24.

2. Ignition coil

The coil steps the battery's 12 volts up to the voltage the plug needs, and on coil-on-plug engines coil 5 serves only cylinder 5. NGK lists worn or deteriorated ignition parts among the causes of a misfire.

A coil that fails from the outside, from oil or water, is the cheap end of this code. The swap section shows how to prove it before buying one.

3. Fuel injector

The injector meters fuel into cylinder 5, so one that clogs leaves too little to burn and one that sticks open floods it. Delphi, an injector maker, says carbon on direct injectors can restrict fuel delivery.

FCA has replaced injectors from a high-flow batch on one V8, and Honda covers the injectors on some 2016 to 2019 Pilot, Ridgeline and Odyssey models to 10 years or 150,000 miles, on the condition in the list below. A shop finds both by VIN, and any injector work on a direct-injection engine belongs at a shop.

Injector bulletins 2 docs

• 2021 Challenger, Charger, Durango, Grand Cherokee, Wrangler, 6.4L. Injectors from a high-flow batch, found by the date code on the fuel rail and each injector; reimbursable under warranty. Bulletin 14-003-22 Rev. A.
• 2016–19 Honda Pilot, 2017–19 Ridgeline, 2018–19 Odyssey. Honda extended the warranty on the fuel injectors, and on some earlier models the engine software update, to 10 years from the original purchase date or 150,000 miles, whichever comes first, for misfire codes P0300 to P0306 and catalyst and fuel-mixture codes. The repair is free only if the dealer finds the codes relate to the injectors or, on some earlier models, the engine software. Owner letters, March 2021.

4. Coolant in the cylinder

The head gasket seals coolant, oil and combustion apart where the cylinder head meets the block. Fel-Pro, a gasket maker, says coolant in a cylinder makes white exhaust smoke, and Victor Reinz names overheating among the reasons a gasket fails.

Coolant leads the Pacifica complaints: 12 of the 15 that name P0305 on 2017 to 2019 Pacificas mention coolant or the head gasket. We found no Chrysler bulletin on it, so a pressure test, not the code, is what confirms it.

5. Worn valvetrain

The valvetrain opens and closes the valves, through cam lobes, lifters and rockers. When a lobe wears flat or a lifter collapses, cylinder 5's valve stops opening fully, and the cylinder can't fill.

Chrysler describes worn intake cam lobes and rocker arms on its 3.6L V6, and GM replaces lifters on some 5.3L and 6.2L trucks and SUVs. Four complaints on 2011 and 2012 Ram 1500s also name a worn cam or lifters behind P0305.

Valvetrain bulletins 2 docs

• 2018–25 Wrangler, Pacifica, Durango, Grand Cherokee, Gladiator, Ram 1500, ProMaster, 3.6L, built before late 2024. Worn intake cam lobes and rocker arms, with rough idle and valvetrain noise; the typical range is 10,000 to 60,000 miles. Bulletin 09-011-25.
• 2020 Silverado and Sierra 1500; 2021 Tahoe, Suburban, Yukon and Escalade; 5.3L and 6.2L built September 2020 to March 2021. A lifter fault with misfire codes P0300 to P0308; the lifters are replaced. Bulletin 23-NA-043.

6. Engine software

The engine computer sets when each plug fires and how much each injector sprays, so its programming can cause a misfire with no failed part. The carmaker's fix is then a reprogram at the dealer.

Toyota's fix names only cylinders 5 and 6, on two V6 models misfiring at full throttle and high revs. Nissan and Ford have also reprogrammed the engine computer for misfire codes that include P0305.

Software bulletins 4 docs

• 2018 Camry, 2019 Avalon, 2GR-FKS V6. Misfire at 5,000 to 6,500 rpm with the pedal floored, codes P0305 and P0306 with the random misfire codes; an engine computer reprogram. Bulletin T-SB-0071-18.
• 2022 Nissan Pathfinder. Misfire codes P0300 to P0306 stored during a cold-start warm-up; an engine computer reprogram. Bulletin NTB22-069.
• 2024 Ford F-150 3.5L PowerBoost, built on or before May 14, 2024. Misfire codes that include P0305; an engine computer reprogram. TSB 24-2191.
• 2021 Ford Transit 3.5L EcoBoost, built on or before July 1, 2021. Misfire codes P0300 to P0306 and P0316; an engine computer reprogram, 0.4 hours. TSB 21-2225.

7. Wiring or fuel delivery

The harness carries the firing signal to coil 5 and injector 5, and the fuel system has to hold enough pressure for that injector to spray. When cylinder 5 passes a compression test, GM's misfire guide points the shop back at spark or fuel.

Owners name wiring or a connector in 5 of the 74 complaints, and none names fuel pressure. A vacuum leak near cylinder 5 is worth a look, but no carmaker document we read ties one to P0305.

How do you tell the coil from the cylinder?

Swap coil 5 with another cylinder's, clear the code and drive. If the misfire moves to the other cylinder, the coil is bad, and if P0305 comes back, the plug and the cylinder are next.

Ford and GM both put that swap in their own diagnosis for some engines. Check your service information first, since some carmakers advise against swapping coils on certain engines, and the P0300 page walks through the whole misfire diagnosis.

When the swap leaves the code on cylinder 5, the carmakers' order starts with the cylinder itself:

• GM: relative compression first. A cylinder that fails goes on to a leakage test and the valvetrain, and one that passes sends the shop back to spark or fuel.
• Volkswagen: leakage test first. Its tech tip for the 2011 to 2014 Routan minivan says to run a cylinder leakage test before replacing any component.

Coil swap in the documents 2 docs

• 2021–22 Ford F-150 3.5L EcoBoost. Swap the coil between the misfiring cylinder and a good one, and replace it only if the misfire follows. Special service message 50412.
• 2012–14 GM direct-injection engines. For a cylinder making little or no power, swap the coil and plug with another cylinder and inspect the plug. Bulletin PIP5062C.

Where is cylinder 5?

Where cylinder 5 sits depends on how the engine's maker numbered it, and only an engine with five or more cylinders has one. Counting from the front of the car is a guess, which the P0300 page explains, and the map in the first section cuts open cylinder 5 on a generic V6 to show its parts, not where it sits on yours.

The nearest a carmaker document comes is Chrysler's 3.6L V6 bulletin, which leak-tests cylinders 2, 4 and 6 and then replaces the left, front head. By our reading that puts cylinder 5 on the other head; on any engine, have the shop point to coil 5 before anything comes off.

What the documents say 2 docs

• 2011–13 Chrysler 3.6L V6. A leak in cylinder 2, 4 or 6 means a new left, front head; the bulletin doesn't name the other head's cylinders. Bulletin 09-002-14 Rev. B.
• GM LTA and LT2 V8s. Cylinder 5 is one of the four, with 2, 3 and 8, that the engine switches off to save fuel. Bulletin 20-NA-038.

How do you fix a P0305 code?

By proving which part failed before you buy one, beginning with the free checks. To fix a P0305 code, work through the 7 steps below, in order:

1. Save every code and its freeze frame. The freeze frame is the snapshot of engine data the computer saves when the code sets. A P0306 or P0300 next to P0305 changes where to look.
2. Check the coolant. A level that keeps dropping with no coolant leak you can see points inside a cylinder. Stop driving and ask for a cooling-system pressure test before anything else.
3. Run the VIN. A dealer checks bulletins, campaigns and software updates by VIN, including Chrysler's plug and injector bulletins. Our free VIN checker shows open recalls and owner complaints first.
4. Swap coil 5 with another cylinder's. Clear the code and drive; if the misfire moves, replace the coil, and if P0305 returns, go to the plug. Check the service information first, or let the shop do it.
5. Pull plug 5 and read it. Check the gap and the insulator for cracks. A plug wet with oil or coolant points past itself, to the cylinder.
6. Have injector 5 checked at a shop. On a 2021 6.4L, the VIN check covers the high-flow batch. On some 2016 to 2019 Pilot, Ridgeline and Odyssey models, Honda pays for the injectors if the dealer finds the codes relate to them.
7. Then test compression and leakage on cylinder 5. A low reading points at a head gasket, a valve or worn valvetrain, and a pass sends the shop back to spark and fuel. Valvetrain noise (a tick) with the misfire means the cam and lifters get looked at too.

The coil swap and reading plug 5 are jobs you can do at home; the injector, compression and leakage tests are shop work. A quote for a new head or engine with no leakage test behind it skips a step GM and Volkswagen both write down, and reading a repair estimate shows what else to ask.

Once the repair is done, clear the code and drive to confirm the light stays off. With the light still on, a car may fail a state or local emissions inspection, as Honda warns its owners.

How much does it cost to fix P0305?

Each part in the box below is under $125 at the counter, so labor and the cause set the bill. It prices them on the F-150, the Silverado and the Ram 1500.

The list below gives US shop averages for the whole job, parts and labor, from a national repair-cost index for 2026, not counter prices. Compare a shop's quote with these, and the parts-only prices in the box with what the part alone costs.

• Spark plugs. $299 for the job, parts and labor, or $480 with coils. US average from a national repair-cost index for 2026.
• Ignition coil. $256 for the job, parts and labor. US average, same index.
• Fuel injector. $572 for the job, parts and labor. US average, same index.

A fault inside the cylinder costs far more than any part in the box, which is why the VIN check comes first. A misfire left running can also lead to a catalytic converter replacement, and head gasket replacement cost covers that job out of warranty.

Dealer labor times 2 jobs

• 2018 Toyota Camry V6, engine computer reprogram. 0.7 hours, covered by Toyota's federal emission warranty. Bulletin T-SB-0071-18.
• 2023 Dodge Challenger 6.2L, re-gap all sixteen plugs. 1.7 hours. Bulletin 09-016-24.

None of the bulletins we read covers cylinder 5 alone, and who pays differs from one to the next. Some are warranty repairs, Toyota's sits under its emission warranty, Honda extended its injector warranty, and FCA's cam bulletin is information only.

Chrysler, Dodge, Jeep and Ram vehicles make up 33 of the 74 complaints, and four FCA bulletins print P0305 by name. On a 3.6L V6 or a 6.2L or 6.4L Hemi, run the VIN before you pay for a plug or a coil, and check what Chrysler, Toyota and GM say for every bulletin.

Which cars report a P0305 code most?

Any engine with five or more cylinders can set P0305, and the Chrysler Pacifica leads the federal complaints. It has 15 of the 74, seven each on the 2017 and 2018 models, ahead of the Ford F-150 with 8.

Twelve of those 15 Pacifica complaints mention coolant or the head gasket, which is the cause described above. These are the models with four complaints or more:

Read these as who reported, not as a failure rate. A model that sells well collects more complaints of every kind.

Which codes come with P0305?

A second code beside P0305 tells you whether cylinder 5 is the whole story. Owners' complaints and carmakers' bulletins list these codes with it:

Codes that come with P0305 3 pairings

• P0306. Named with P0305 in 13 of the 74 complaints; Toyota's high-load bulletin lists only these two cylinder codes, with P0300.
• P0304 and P0306. On the 2011 to 2013 F-150 3.5L, the three together point at Ford's humid-weather misfire, ASI 32166.
• P0300. Listed with P0305 in 22 of the 74 complaints; the P0300 page covers the random misfire code.

OBD-II · Misfire codes

Other OBD-II misfire codes and what each one means

1. P0300 random misfire

2. P0301 cylinder 1

3. P0302 cylinder 2

4. P0303 cylinder 3

5. P0304 cylinder 4

6. P0306 cylinder 6

What are the symptoms of a P0305 code?

A check engine light, steady or flashing, with lost power, stalling, shaking or a rough idle. Owners who reported P0305 to federal regulators name lost power most, in 18 of the 74 complaints.

A flashing light means the misfire is strong enough to put the catalytic converter at risk, and the other signs say how hard cylinder 5 is missing. Here's what each one tells you:

• Lost power or hesitation. One cylinder has stopped pulling its share; jerking when accelerating explains the feel and the other causes.
• Stalling or a rough idle. The miss is strong enough to show at a standstill, or to stop the engine.
• Shaking or vibration. The engine turns unevenly because one cylinder isn't firing.
• A flashing check engine light. The computer's warning that the misfire could overheat the catalytic converter.

Common questions

Asked most often

What is the most common cause of a P0305 code?

In the 74 federal complaints, owners name the spark plug in 24, coolant in 18 and the coil in 17. On the Chrysler Pacifica coolant leads, in 12 of 15.

Which side of the engine is cylinder 5 on?

It depends on the engine's maker. Chrysler's 3.6L V6 bulletin leak-tests cylinders 2, 4 and 6 and then replaces the left, front head, which by our reading leaves cylinder 5 on the other one; on any engine, have the shop point to coil 5.

Why is there a P0305 after changing the spark plugs?

Then the plug wasn't the whole cause. A 2011 Ram 1500 had new plugs and a coil, and the light came back within 12 miles until the mechanic found a worn cam.

Do P0305 and P0306 together mean the same fault?

Not always, but 13 of the 74 complaints list both. Toyota's bulletin for the 2018 Camry and 2019 Avalon V6 names only those two cylinders, and its fix is software.

Can a vacuum leak cause a P0305 code?

Not according to the documents we read: no carmaker bulletin ties a vacuum leak to P0305. Treat it as a check after the coil swap and plug 5.

Is P0305 covered by warranty?

Sometimes: Chrysler's cracked-plug and 6.4L injector bulletins are reimbursable under warranty, and Toyota's reprogram falls under its emission warranty. Honda covers the injectors on some 2016 to 2019 Pilot, Ridgeline and Odyssey models to 10 years or 150,000 miles, free only if the dealer finds the codes relate to the injectors or, on some earlier models, the engine software.

Prices are ranges compiled in September and 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.