P0304 on Kia vehicles Cylinder 4 is misfiring
P0304 is named on 21 Kia model years (2016–2025): 16 manufacturer filings and 21 owner reports in NHTSA’s files, across Forte, Sedona, Seltos, Sorento, Soul and 3 more.
Which Kia model years name P0304
Source: NHTSA manufacturer communications and complaints| Model year | Filed under | Bulletins | Owner reports |
|---|---|---|---|
| 2017 Kia Forte | Engine | 7 | — |
| 2018 Kia Forte | Engine | 6 | — |
| 2021 Kia Seltos | Engine | — | 2 |
| 2021 Kia Soul | Engine | — | 2 |
| 2020 Kia Sorento | Engine | — | 2 |
| 2019 Kia Forte | Engine | 2 | — |
| 2016 Kia Sedona | Engine | — | 2 |
| 2025 Kia Sorento | Engine | — | 1 |
| 2023 Kia Forte | Electrical System | — | 1 |
| 2023 Kia Soul | Power Train | — | 1 |
| 2022 Kia Sorento | Power Train | — | 1 |
| 2020 Kia Optima | Engine | — | 1 |
| 2020 Kia Soul | Engine | — | 1 |
| 2020 Kia Telluride | Engine | — | 1 |
| 2018 Kia Rio | Electrical System | 1 | — |
| 2018 Kia Sorento | Engine | — | 1 |
| 2017 Kia Optima | Engine | — | 1 |
| 2017 Kia Sedona | Engine | — | 1 |
| 2016 Kia Optima | Engine | — | 1 |
| 2016 Kia Sorento | Engine | — | 1 |
| 2016 Kia Soul | 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.
What Kia owners said
Source: NHTSA complaint databaseOwners’ own words, scrubbed of anything identifying. Unverified reports filed with NHTSA — what was said, not a finding that it was true.
It has done it three different times the last time it through a code on my OBD monitor read it and said P0304 the 4th cylinder is misfiring
Kia filings that name P0304
Source: NHTSA manufacturer communicationsBulletins and campaigns Kia 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.
- TSB-ENG165 Service bulletin2017-04-11 · Electrical System
- TSB: SERVICE ACTION: ECU LOGIC IMPROVEMENT FOR DTC P030X (SA285) - This bulletin provides the procedure to improve the logic of the Electronic Control Unit (ECU) on some 2017MY Forte (YDm) vehicles equipped with 2.0L MPI engine, produced from May 30, 2016 to February 22, 2017, which may experience a malfunction indicator lamp illumination with DTC P0300, P0301, P0302, P0303, or P0304. To correct t
- TSBENG165R1 Service bulletin2017-06-05 · Engine
- TSB: SERVICE ACTION: ECU LOGIC IMPROVEMENT FOR DTC P030X (SA285) - This bulletin provides the procedure to improve the logic of the Electronic Control Unit (ECU) on some 2017MY Forte (YDm) vehicles equipped with 2.0L MPI engine, produced from May 30, 2016 to February 22, 2017, which may experience a malfunction indicator lamp illumination with DTC P0300, P0301, P0302, P0303, or P0304. To correct t
- TSBENG181 Service bulletin2017-12-12 · Electrical System — Ignition
- TSB - SERVICE ACTION: IGNITION COIL OR COIL RFI SPRING REPLACEMENT FOR DTC P030X (SA321) - This bulletin provides the procedure to replace all four (4) ignition coils or replace all four (4) coil radio frequency interference (RFI) springs on some 2017-2018MY Forte (YDm) 2.0L MPI vehicles, produced from May 16, 2017 through September 7, 2017, which may experience a malfunction indicator lamp illumi
- TSBENG186 Service bulletin2018-04-30 · Electrical System
- TSB - SERVICE ACTION: SPARK PLUG REPLACEMENT (SA342) - This bulletin provides the procedure to replace the spark plugs on some 2018MY Forte (YDm), produced from November 21, 2017 through April 12, 2018, and 2018MY Rio (SC) vehicles, both produced from November 22, 2017 through February 6, 2018, which may exhibit a malfunction indicator lamp (MIL) ON with DTCs P0300 through P0304 due to the spark p
- TSBENG208 Service bulletin2019-06-26 · Engine And Engine Cooling
- TSB: ECU LOGIC IMPROVEMENT FOR P0300, P0301, P0302, P0303, P0304 AND/OR P219C00, P219D00, P219E00, P219F00 - This bulletin provides the procedure to improve the logic of the Engine Control Module (ECM) on some 2017-2018MY Forte (YDm) vehicles, produced from May 15, 2016 through July 27, 2018, which may experience a malfunction indicator lamp (MIL) ON with DTC P0300, P0301, P0302, P0303, P0304 and/
- TSBENG204_R1 Service bulletin2019-05-24 · Engine And Engine Cooling
- TSB: SERVICE ACTION: ECU LOGIC IMPROVEMENT FOR P0300, P0301, P0302, P0303, P0304 AND/OR P219C00, P219D00, P219E00, P219F00 (SA378) - This bulletin has been revised to include additional information. This bulletin provides the procedure to improve the logic of the Engine Control Unit (ECU) on some 2019MY Forte (BDm) vehicles, equipped with a NU 2.0MPI Atkinson engine and produced from July 9, 2018
- TSBENG181_R1 Service bulletin2019-10-16 · Engine And Engine Cooling
- TECHNICAL SERVICE BULLETIN TSBENG181_R1: SERVICE ACTION: IGNITION COIL OR COIL RFI SPRING REPLACEMENT FOR DTC P0300, P0301, P0302, P0303, AND/OR P0304 (SA321) - This bulletin provides the procedure to replace all four (4) ignition coils or replace all four (4) coil radio frequency interference (RFI) springs on some 2017-2018MY Forte (YDm) 2.0L MPI vehicles, produced from May 16, 2016 through Sept
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 Kia 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 Kia vehicles?
It is a documented one: NHTSA's files hold 16 manufacturer filings and 21 owner reports naming P0304 on 21 Kia model years (2016–2025). 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 Kia models does P0304 appear on most?
2017 Forte (7 documents), 2018 Forte (6 documents), 2019 Forte (2 documents).
Does P0304 on a Kia 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.