P0304 on Mazda vehicles Cylinder 4 is misfiring
P0304 is named on 20 Mazda model years (2016–2021): 39 manufacturer filings and 2 owner reports in NHTSA’s files, across CX-5, Mazda3, Mazda6, CX-3, CX-30 and 1 more.
Which Mazda model years name P0304
Source: NHTSA manufacturer communications and complaints| Model year | Filed under | Bulletins | Owner reports |
|---|---|---|---|
| 2016 Mazda CX-5 | Engine | 6 | — |
| 2016 Mazda Mazda3 | Engine | 6 | — |
| 2016 Mazda Mazda6 | Engine | 5 | — |
| 2019 Mazda CX-5 | Engine | 2 | 1 |
| 2018 Mazda Mazda6 | Engine | 3 | — |
| 2021 Mazda Mazda3 | Engine | 1 | 1 |
| 2019 Mazda Mazda6 | Engine | 2 | — |
| 2018 Mazda CX-5 | Engine | 2 | — |
| 2021 Mazda CX-30 | Engine | 1 | — |
| 2020 Mazda CX-30 | Engine | 1 | — |
| 2020 Mazda CX-5 | Engine | 1 | — |
| 2020 Mazda CX-9 | Engine | 1 | — |
| 2020 Mazda Mazda3 | Engine | 1 | — |
| 2020 Mazda Mazda6 | Engine | 1 | — |
| 2019 Mazda CX-9 | Engine | 1 | — |
| 2018 Mazda CX-9 | Engine | 1 | — |
| 2017 Mazda CX-3 | Equipment | 1 | — |
| 2017 Mazda CX-9 | Engine | 1 | — |
| 2016 Mazda CX-3 | Equipment | 1 | — |
| 2016 Mazda CX-9 | Engine | 1 | — |
A model year is listed because the code is named in its own record — a bulletin filed against it, or an owner’s complaint about it — not because every one of these vehicles sets it. Counts are documents in NHTSA’s files, not failure rates.
Mazda filings that name P0304
Source: NHTSA manufacturer communicationsBulletins and campaigns Mazda filed with NHTSA whose summary names P0304. Quote the document number at the service desk — it is a diagnosis the maker has already written down.
- 01-014-16-3208A Service bulletin2016-07-29 · Engine
- SOME VEHICLES MAY EXPERIENCE A LACK OF ENGINE POWER/ROUGH IDLING AND THE CHECK ENGINE LIGHT ON WITH ONE OR MORE OF THE MISFIRE RELATED DTCS OF P0300:00, P0301:00, P0302:00, P0303:00 AND P0304:00. THIS CONCERN MAY BE CAUSED BY AN INTERNAL FAILURE OF THE IGNITION COIL(S) DUE TO A HIGH DIFFERENCE BETWEEN COLD AND WARM AMBIENT TEMPERATURES. THE PRODUCTION METHOD OF THE IGNITION COIL HAS BEEN CHANGED T
- 01-014-16-3208A Service bulletin2016-07-29 · Engine
- SOME VEHICLES MAY EXPERIENCE A LACK OF ENGINE POWER/ROUGH IDLING AND THE CHECK ENGINE LIGHT ON WITH ONE OR MORE OF THE MISFIRE RELATED DTCS OF P0300:00, P0301:00, P0302:00, P0303:00 AND P0304:00. THIS CONCERN MAY BE CAUSED BY AN INTERNAL FAILURE OF THE IGNITION COIL(S) DUE TO A HIGH DIFFERENCE BETWEEN COLD AND WARM AMBIENT TEMPERATURES. THE PRODUCTION METHOD OF THE IGNITION COIL HAS BEEN CHANGED T
- 01-014-16-3208 Service bulletin2016-06-10 · Engine
- SOME VEHICLES MAY EXPERIENCE A LACK OF ENGINE POWER/ROUGH IDLING AND THE CHECK ENGINE LIGHT ON WITH ONE OR MORE OF THE MISFIRE RELATED DTCS OF P0300:00, P0301:00, P0302:00, P0303:00 AND P0304:00. THIS CONCERN MAY BE CAUSED BY AN INTERNAL FAILURE OF THE IGNITION COIL(S) DUE TO A HIGH DIFFERENCE BETWEEN COLD AND WARM AMBIENT TEMPERATURES. THE PRODUCTION METHOD OF THE IGNITION COIL HAS BEEN CHANGED T
- 01-017-16-3242 Service bulletin2016-08-26 · Engine
- SOME VEHICLES MAY EXPERIENCE AN ENGINE THAT RUNS ROUGH AND THE CHECK ENGINE LIGHT ON WITH DTCS P0201 AND P0204 OR P0202 AND P0203. NOTE:ENGINE MISFIRE RELATED DTCS (P0301, P0302, P0303, P0304) ARE USUALLY STORED AT THE SAME TIME. P0201:00: FUEL INJECTOR CIRCUIT/OPEN CYLINDER NO.1P0202:00: FUEL INJECTOR CIRCUIT/OPEN CYLINDER NO.2P0203:00: FUEL INJECTOR CIRCUIT/OPEN CYLINDER NO.3P0204:00: FUEL INJEC
- SA-022-19 Service bulletin2019-05-29 · Engine
- If you receive a customer complain of lack of power, rough idle, engine noise with stored DTC's P0340:00, P0304:00, P3400:00, P349B:00, and/or P3498:00, perform the following.
- 01-001-23a Service bulletin2023-02-03 · Engine And Engine Cooling
- Some customers may complain about a poor acceleration and rough idling or the CHECK ENGINE light ON with DTC P0301:00, P0302:00, P0303:00, P0304:00. NOTE: Only turbo engines are applicable; non-turbo engines are NOT applicable. In most cases, DTCs P030X stores, but sometimes not. Sometimes the CHECK ENGINE light does not recognize this engine concern. This is caused by the variable valve in the e
- SA-041-18 Service bulletin2018-12-06 · Engine
- If you receive a customer complain of lack of power, rough idle, engine noise with stored DTC's P0340:00, P0304:00, P3400:00, P349B:00, and/or P3498:00, perform the following.
- 01-004-17-3317a Service bulletin2017-07-05 · Equipment — Other — Owners/Service/Other Manual
- Some vehicles may experience an engine that runs rough and the check engine light on with DTCs P0201 and P0204 or P0202 and P0203. NOTE: Engine misfire related DTCs (P0301, P0302, P0303, P0304) are usually stored at the same time. P0201:00 : Fuel injector circuit/open cylinder No.1 P0202:00 : Fuel injector circuit/open cylinder No.2 P0203:00 : Fuel injector circuit/open cylinder No.3 P0204:00 : Fu
What P0304 means
Source: SAE J2012 / OBD-IICylinder 4 is misfiring.
A stored code names the test that failed, never the part that caused it. The record above is what Mazda and its owners have filed about it; the code’s page across every make has the whole file.
Common questions
Source: NHTSA files and the OBD-II standardIs P0304 a known problem on Mazda vehicles?
It is a documented one: NHTSA's files hold 39 manufacturer filings and 2 owner reports naming P0304 on 20 Mazda model years (2016–2021). Whether it is a problem on one particular car is a diagnosis, not a count — but a bulletin that names the code on your model year is the place to start.
Which Mazda models does P0304 appear on most?
2016 CX-5 (6 documents), 2016 Mazda3 (6 documents), 2016 Mazda6 (5 documents).
Does P0304 on a Mazda mean it is recalled?
No. Recalls are filed by campaign and matched by VIN; no recall is triggered by a scan tool. Check the VIN at nhtsa.gov/recalls, or open the model year's page here for the campaigns filed against it.