What does code P0304 mean on a Jeep and is it safe to drive?
P0304: Cylinder 4 Misfire Detected. Here's what it means on your Jeep, what usually causes it, what repairs typically cost, and how safe it is to keep driving.
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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 Jeep
- 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 Jeep, 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 Jeep
Jeep 3.6L Pentastar P0304 is a front-bank misfire. Cam follower wear on the front bank is less common than the rear but does occur. Check for a tick at startup and inspect follower condition on high-mileage engines before replacing the coil.
Most commonly affected models
Grand Cherokee 3.6L 2011–2020Wrangler 3.6L 2012–2018Cherokee 2.4L 2014–2018