HomeP0304 · Engine misfire detected · Cylinder 4
Powertrain

P0304

Engine misfire detected · Cylinder 4

P0304
Reference meaning

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.

A code identifies a detected condition, not a part that must automatically be replaced.

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A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.

Manufacturer communications

4

Original wording in English

99121

FORD, MERCURY

Reported code forms P0304

SUBJECT REGARDING THE MALFUNCTION INDICATOR LAMP (MIL) ILLUMINATED AND DIAGNOSTIC TROUBLE CODES (DTCS) P0300, P0302, P0303, P0304, P0305, AND / OR P0306 STORED IN MEMORY. *TT

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983590

FORD, MERCURY

Reported code forms P0304

INFORMATION REGARDING THE MALFUNCTION INDICATOR LIGHT (MIL) AND MISFIRE DIAGNOSTIC TROUBLE CODES (DTCS) P0300, P0301, P0302, P0303, P0304, P0305, AND P0306 WITH NO DRIVEABILITY CONCERNS. *TT

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96265

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

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962510

FORD, LINCOLN, 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

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Check vehicle applicability

2

A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.

MakeModelModel year
FordCONTOUR1998
FordCONTOUR1996

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.

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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.

  1. 01 13 14 / 2033805 · Engine, Misfire Diagnostic Aid ↗

    Volkswagen Group of America · PDF page(s) 1, 2 ·

  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.