What does this code mean?
P0300 indicates random or multiple-cylinder misfire. P0301–P0308 identify the numbered cylinder. Ignition, fuel delivery, compression, air leaks or mechanical timing can cause misfire. Use misfire counters, freeze-frame data and appropriate tests to narrow the cause. A flashing malfunction light can signal a misfire that may damage the catalyst.
Sources and interpretation [1]
A code identifies a detected condition, not a part that must automatically be replaced.
Manufacturer wording
Source wording can vary by vehicle and suffix. It is shown as written, not as a universal diagnosis.
P0304MISFIRE CYLManufacturer communications
8Original wording in English
FORD
Reported code forms P0304
Some 2015-2017 Focus ST vehicles may exhibit MIL On with a perceived Misfire after cold start. Diagnostic Trouble Codes DTC's) may include P0300, P0301, P0302, P0303,P0304, and P0316. Refer to General Service Bulletin…
FORD
Reported code forms P0304
MIRFIRE DIAGNOSTIC TROUBLE CODES P0316, P0300, P0301, P0302, P0303, OR P0304 - SERVICE TIP. *TT
FORD
Reported code forms P0304
DTC P0316, P0300, P0301, P0302, P0303 AND/OR P0304 - SERVICE TIP. *TT
FORD
Reported code forms P0304
ROUGH IDLE, LOW POWER AND / OR STALL AT IDLE, A MALFUNCTION INDICATOR LAMP ILLUMINATED AND DIAGNOSTIC TROUBLE CODES P0300 THROUGH P0304 STORED IN MEMORY. *TT
FORD, MERCURY
Reported code forms P0304
SOME VEHICLES EQUIPPED WITH THE 2.0L SPI ENGINE MAY EXHIBIT A MALFUNCTION INDICATOR LAMP (MIL) ILLUMINATED AND DIAGNOSTIC TROUBLE CODES (DTC) P0300 THROUGH P0304 STORED. *TT
FORD
Reported code forms P0304
MALFUNCTION INDICATOR LAMP (MIL) ILLUMINATED AND DIAGNOSTIC TROUBLE CODES (DTCS) P0300 THROUGH P0304 STORED IN MEMORY SOME VEHICLES EQUIPPED WITH THE 2.0L SPI ENGINE. *TT
Check vehicle applicability
11A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.
Before replacing a part
Record codes and freeze-frame data. Check battery condition, related codes and visible wiring or hose damage. Follow the vehicle's diagnostic procedure and test results before replacing parts.
Sources and interpretation
These explanations are editorial summaries of the linked manufacturer material. PDF page numbers count from the first file page. Original publications are in English; translations are reference aids. A cited edition is not a claim that it is the manufacturer's latest instruction.
- 01 13 14 / 2033805 · Engine, Misfire Diagnostic Aid ↗
Volkswagen Group of America · PDF page(s) 1, 2 ·
- 2024–2025 MY OBD System Operation Summary for Gasoline Engines ↗
Ford Motor Company · PDF page(s) 9, 10 ·
Source check date · 2026-10-27
Can I keep driving?
A code alone cannot establish whether driving is safe. A flashing malfunction light, severe shaking, overheating, oil-pressure warning or loss of braking or steering needs prompt attention. Stop in a safe place and seek assistance when control or engine safety is affected. Follow the vehicle handbook.