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 communications
7Original wording in English
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, MERCURY
Reported code forms P0304
SOME VEHICLES MAY EXHIBIT A CUSTOME CONCERN OF STEADY OR INTERMITTENT MISS WITH DIAGNOSTIC TROUBLE CODES P0300 AND P0304. *TT
FORD, MERCURY
Reported code forms P0304
SOME VEHICLES MAY EXHIBIT A CUSTOMER CONCERN OF STEADY OR INTERMITTENT MISS WITH DTCS P0300 AND P0304. THIS MAY BE CAUSED BY A SPREAD ELECTRICAL TERMINAL IN CONNECTORS AT INJECTOR. REPAIR TERMINAL/CONNECTOR CONCERN BY…
FORD, MERCURY
Reported code forms P0304
CONDITION REGARDING THE ENGINE MISFIRE CODE ( DTC P0304 ). *YC
FORD, MERCURY
Reported code forms P0304
MALFUNCTION INDICATOR LAMP (MIL) - DIAGNOSTIC TROUBLE CODES (DTCS) P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, AND/OR P0308 STORED IN MEMORY. *TW
Check vehicle applicability
7A 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.