Engine Misfire
Code P0304
Cylinder 4 Misfire
Plain English Meaning:Cylinder 4 misfire detected causing poor combustion
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Red: Stop Driving & Tow
Can damage catalytic converter quickly
P0304 Symptoms
- •Rough running shaking loss of power
Most Common Causes of P0304
1Ignition failure injector problem low compression
P0304 Repair Playbook
Required Mechanic Tests
A qualified shop should perform these tests before replacing any parts to ensure they aren't guessing:
Test spark swap coil compression test
Typical Fix Paths & Estimated Costs
Repair ignition or injector $100–$1200
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Parts for P0304 Repair
Common replacement parts for engine misfire codes. (Paid links)
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