What does code P0304 mean on a Chevrolet and is it safe to drive?
P0304: Cylinder 4 Misfire Detected. Here's what it means on your Chevrolet, what usually causes it, what repairs typically cost, and how safe it is to keep driving.
What this code means
Misfire confirmed on cylinder 4. On 4-cylinder engines, this is the last cylinder—check coil and plug first, then injector, then compression.
Common causes for your Chevrolet
- Worn spark plug on cylinder 4
- Failed ignition coil on cylinder 4
- Faulty or clogged fuel injector
- Low compression or valve issue
Symptoms
- Check Engine Light
- Rough idle and shaking
- Poor acceleration or power loss
Typical fixes
- Replace spark plug and COP coil on cylinder 4
- Clean or replace fuel injector
- Compression and leak-down test if basic parts check out
Repair cost range
For a Chevrolet, repairs for P0304 often fall between $150 and $900, depending on the cause and whether you use OEM or aftermarket parts. Labor rates vary by location.
Known issues on Chevrolet
On the turbocharged 1.4L LUV engine in Cruze and Sonic, P0304 can indicate a blown ignition coil or a fuel injector issue—turbo engines are harder on plugs and coils. On 5.3L AFM V8, cylinder 4 is active so coil or plug failure is the typical cause.
Most commonly affected models