P0304 on Acura vehicles Cylinder 4 is misfiring
P0304 is named on 11 Acura model years (2017–2026): 26 manufacturer filings and 5 owner reports in NHTSA’s files, across Integra, ADX, MDX, RDX.
Which Acura model years name P0304
Source: NHTSA manufacturer communications and complaints| Model year | Filed under | Bulletins | Owner reports |
|---|---|---|---|
| 2026 Acura Integra | Engine | 5 | — |
| 2025 Acura Integra | Engine | 5 | — |
| 2024 Acura Integra | Engine | 5 | — |
| 2023 Acura Integra | Engine | 5 | — |
| 2026 Acura ADX | Engine | 3 | — |
| 2025 Acura ADX | Engine | 3 | — |
| 2023 Acura RDX | Engine | — | 1 |
| 2019 Acura MDX | Engine | — | 1 |
| 2019 Acura RDX | Engine | — | 1 |
| 2018 Acura MDX | Engine | — | 1 |
| 2017 Acura RDX | Electronic Stability Control | — | 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.
Acura filings that name P0304
Source: NHTSA manufacturer communicationsBulletins and campaigns Acura 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.
- BEBM08262026901 Other2026-08-26 · Engine
- Dealer Message - Under certain conditions, the cylinder head gasket effectiveness may be reduced which may cause vehicles to experience overheating, coolant loss, misfire, and/or DTCs P0300 through P0304 stored.
- B26-002 Service bulletin2026-08-26 · Engine
- Service Bulletin - Under certain conditions, the cylinder head gasket effectiveness may be reduced which may cause vehicles to experience overheating, coolant loss, misfire and/or DTCs P0300 thru P0304 stored.
- B26-003 Service bulletin2026-08-26 · Engine
- Service Bulletin - Under certain conditions, the cylinder head gasket effectiveness may be reduced which may cause vehicles to experience overheating, coolant loss, misfire and/or DTCs P0300 thru P0304 stored.
- B26-001 Service bulletin2026-08-26 · Engine
- Service Bulletin - Under certain conditions, the cylinder head gasket effectiveness may be reduced which may cause vehicles to experience overheating, coolant loss, misfire and/or DTCs P0300 thru P0304 stored.
- B26-001 Service bulletin2026-09-25 · Engine
- Service Bulletin - Under certain conditions, the cylinder head gasket effectiveness may be reduced which may cause vehicles to experience overheating, coolant loss, and/or misfire. In some cases, DTCs P0300 through P0304 may also be stored (DTCs are not required for repair).
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 Acura 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 Acura vehicles?
It is a documented one: NHTSA's files hold 26 manufacturer filings and 5 owner reports naming P0304 on 11 Acura model years (2017–2026). 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 Acura models does P0304 appear on most?
2026 Integra (5 documents), 2025 Integra (5 documents), 2024 Integra (5 documents).
Does P0304 on a Acura 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.