OBD-II Generic Error Code P0278: How to Fix It
Medium 1-3 hours Medium Severity
Verified June 2026
- Error Code
- P0278
- Brand
- OBD-II Generic
- Product Type
- automotive
- Severity
- Medium
- DIY Difficulty
- Medium
- Estimated Fix Time
- 1-3 hours
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Tools You'll Need
- OBD-II scanner
- Socket set
- Spark plug socket
- Multimeter
- Noid light
- Compression tester
- Mechanic's stethoscope
How to Fix Error Code P0278
-
Read the Code and Record Freeze Frame Data
Ensure the ignition is off when connecting the scanner. -
Inspect Cylinder 6 Components Visually
Let the engine cool before touching components. -
Swap Ignition Coil with Another Cylinder
-
Test Fuel Injector Operation
Fuel system is under pressure; relieve pressure before disconnecting lines. -
Perform a Compression Test
Disable the fuel and ignition system to prevent starting during the test. -
Replace Faulty Injector, Coil, or Spark Plug
Use approved parts for your vehicle make/model.
Parts You May Need
Fuel injector for Cylinder 6
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Ignition coil
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Spark plug
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Fuel injector for Cylinder 6
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Ignition coil
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Spark plug
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Fuel injector for Cylinder 6
Check Price on Amazon
Ignition coil
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Spark plug
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Fuel injector for Cylinder 6
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Ignition coil
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Spark plug
Check Price on Amazon
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When to Call a Professional
If you have no mechanical experience, or if compression is low indicating internal engine damage. Also if the code persists after replacing injector/coil/plug, you may need professional diagnostic equipment.Frequently Asked Questions
What does P0278 mean?
P0278 means Cylinder 6 is not contributing to engine power, commonly due to a bad fuel injector, ignition coil, spark plug, or internal engine problem.
Can I drive with a P0278 code?
You can drive short distances, but it may cause rough idle, misfire, and reduced power. Prolonged driving can damage the catalytic converter.
How much does it cost to fix P0278?
DIY cost: $20-$150 for a spark plug, $50-$200 for an ignition coil, or $50-$300 for a fuel injector. Professional repair: $150-$1000 depending on labor.
Is P0278 the same as a misfire?
Yes, P0278 is a specific misfire code for Cylinder 6. It often comes with a generic misfire code like P0300.
What other codes might appear with P0278?
Common companion codes: P0300 (random misfire), P0306 (Cylinder 6 misfire), P0206 (injector circuit).