The Lemon IndexCylinder 4 is not firing properly, so the engine runs rough and loses some power. Full P0304 page
14 owner complaints · the #5 code Honda Pilot owners name · 7% of Honda Pilot complaints that name a code (every car: 2.4%)
Middle of 87,000 miles · most between 66,000 and 90,000 (5 owners gave it)
Honda Pilot owners named P0304 in 14 complaints to the U.S. government (NHTSA), most often on the 2016, 2019 and 2015 model years, at a middle of 87,000 miles. The part they name most is the fuel injectors (4 complaints). Complaints are owner reports, not proof of a defect.
Honda Pilot model years that report P0304
Owner complaints naming P0304, by model year. Raw counts: years that sold more get more complaints, so this is each model year's record, not a failure rate.
Mileage when it happened
87,000 miles is the middle of what 5 owners entered. Half were between 66,000 and 90,000 miles.
The mileage on the complaint form, when the owner gave one.
What owners say caused it or fixed it
The most-named part is the fuel injectors, in 4 of the 14 complaints (29%). 3 of those mention it being replaced or repaired, and 1 say the problem came back afterwards. Next: spark plugs (4) and pistons, rings or valves (3).
- Fuel injectors4 complaints3 mention a repair or replacement, 1 of them says the problem came back · what Honda Pilot owners paid
- Spark plugs4 complaints3 mention a repair or replacement · what Honda Pilot owners paid
- Pistons, rings or valves3 complaints1 mentions a repair or replacement, 1 of them says the problem came back
6 mention a warranty.
Counted from the owners' own words: a part counts when a sentence names it with a cause or repair word. What owners wrote, not a diagnosis. A shop should confirm the cause before replacing parts.
Symptoms owners describe with P0304
43% of these complaints say the check engine light came on.
- Shakes, runs rough or misfires64%9 of 14 complaints
- Warning lights and electrical faults14%2 of 14 complaints
- Won't start or hard to start14%2 of 14 complaints
Share of the complaints naming P0304 whose text also describes each problem. A complaint can describe more than one.
Codes owners report with it
P0301 3 P0430 3 P0306 2 P0300 2
Other codes named in the same Honda Pilot complaints, and in how many.
Repair costs
Honda Pilot fuel injector replacement cost · Honda Pilot spark plug replacement cost
Recalls on these Honda Pilot years
- Fuel system, gasoline · 2015, 2016, 2017, 2019 · issued 2023
The fuel pump inside the fuel tank may fail. NHTSA 23V858000 - Engine · 2016, 2019 · issued 2023
Due to a manufacturing error, the connecting rod bearing in the engine may wear and seize, damaging the engine. NHTSA 23V751000 - Fuel system, gasoline · 2019 · issued 2021
The low-pressure fuel pump inside the fuel tank may fail. NHTSA 21V215000 - Engine · 2019 · issued 2019
The timing belt teeth may separate from the belt. NHTSA 19V298000 - Fuel system, gasoline · 2016 · issued 2017
The affected vehicles have fuel tanks that may leak. NHTSA 17V219000
8 recalls for the same systems (engine and fuel) on the Honda Pilot model years above. A recall for the same system isn't proof it's behind P0304. Recall work is free at any dealer: check a VIN at nhtsa.gov/recalls or with our VIN check.
Keep going
- P0304: meaning, causes and every car that reports it
- Honda Pilot reliability by year
- 2016 Honda Pilot problems and recalls
Other codes Honda Pilot owners report
P0430 U3000 P219A P219B P0369 P0741 P0087 P0301 P0420
P0304 on other cars
Ford Escape (49) · Ford Edge (31) · Honda CR-V (23) · Honda Accord (20) · Honda Odyssey (19) · Ford Fusion (16) · Kia Sorento (10)
The details
How we count
We read every owner complaint in the NHTSA file whose text names this trouble code, and count the ones filed about this model (matched by the make, model and model year on the complaint). Mileage is what the owner entered on the form.
Parts: a complaint counts for a part when one of the owner's own sentences names that part together with a cause word (failed, bad, diagnosed, caused by, leaking ...) or a repair word (replaced, repaired, new, reprogrammed ...). "Came back" means the same complaint also says the problem returned or the repair didn't fix it. These are counts of what owners wrote, not a diagnosis, and one complaint can name several parts.
Complaints are reports, not proof of a defect, and most owners never file one. Popular models get more complaints, so the counts are not a failure rate. The code meaning is the standard SAE J2012 definition in our own words, or the carmaker's meaning where we verified it for that make.
What P0304 means
Cylinder 4 is not firing properly, so the engine runs rough and loses some power. A flashing check engine light means the misfire is serious enough to damage the catalytic converter, so slow down and get it checked right away.
Get it fixed soon. A few more days of normal driving is usually OK, but waiting can turn a small repair into a bigger one or a breakdown.
- Spark plug or ignition coil on cylinder 4
- Fuel injector on cylinder 4
- Vacuum leak near that cylinder
- Low compression (valve or piston ring problem)
Check the complaints yourself
NHTSA complaint numbers (search them at nhtsa.gov): 11773820, 11771719, 11737134, 11730771, 11720683, 11685705, 11586475, 11515128, 11389274, 11338018, 11331364, 11322065 and 2 more.
Quick answers
What does P0304 mean on a Honda Pilot?
Cylinder 4 Misfire Detected. Cylinder 4 is not firing properly, so the engine runs rough and loses some power. A flashing check engine light means the misfire is serious enough to damage the catalytic converter, so slow down and get it checked right away.
Which Honda Pilot years have the most P0304 complaints?
In complaints to NHTSA, owners of the 2016 (4), 2019 (2), 2015 (2) Honda Pilot named P0304 most (14 complaints in all, 2011–2019). Raw counts, not a failure rate.
What fixes P0304 on a Honda Pilot?
Owners most often name the fuel injectors (4 of 14 complaints), then spark plugs and pistons, rings or valves. That's what owners wrote, not a diagnosis: have a shop confirm the cause with a scan and tests before replacing parts.
At what mileage does P0304 show up on a Honda Pilot?
Owners who gave their mileage reported a middle of 87,000 miles; half were between 66,000 and 90,000 (5 owners).
Can I drive my Honda Pilot with P0304?
Get it fixed soon. A few more days of normal driving is usually OK, but waiting can turn a small repair into a bigger one or a breakdown.
Sources: NHTSA owner complaints that name P0304 on the Honda Pilot, counted by The Lemon Index; NHTSA recalls; repair bills owners named. Meanings: SAE J2012 in our own words. Owner reports, not a diagnosis or repair advice for your car.