The OBD-II code P0305 means that the powertrain control module (PCM) has detected a misfire in one of the engine’s cylinders. It usually stems from a problem with the ignition system, fuel system, or internal engine components.
Read this guide to learn more about the P0305 error code—what it means, its symptoms and causes, as well as tips for diagnosis and repair.
Diagnostic trouble code (DTC) P0305 stands for “Cylinder 5 Misfire Detected.” This means that the powertrain control module (PCM) has counted enough misfire events on cylinder 5 to store the misfire code for that cylinder.
If you need help locating the misfiring cylinder, read our guide about cylinder location and firing order. You may also read our technical discussion about how the engine computer identifies which cylinder is misfiring.
Otherwise, continue reading to learn the most common causes of the P0305 code.
A thorough diagnosis can pinpoint the exact cause of code P0305. Common causes of the code include:
Note: If there are other codes stored in addition to P0305, the causes and symptoms may differ from those listed here.
Below are the most common symptoms that accompany the error code P0305 or a cylinder 5 misfire:
A misfire on cylinder 5 isn’t something to shrug off. The engine can stumble, lose power at the wrong moment, or even cut out while you’re driving, which is more than just inconvenient. Left unchecked, the constant misfiring can overheat and destroy the catalytic converter, warp valves, or trigger other damage that snowballs into bigger repair bills.
As for fixing it, the difficulty swings wildly depending on what’s wrong. Swapping out a fouled spark plug or a weak ignition coil is straightforward if you have basic tools. Tracking down a bad injector, a wiring fault, or worn valvetrain parts is another story. These jobs demand diagnostic gear, time, and a solid grasp of how the engine works. Without that, you’re mostly guessing and throwing parts at the problem.
If you’d rather skip the guesswork, hand the car over to a mechanic and let them trace the misfire with the right equipment. You can still bring your own parts to the shop, which is a simple way to cut down the cost of the repair.
Because there are so many potential causes for code P0305, diagnosis can be difficult. The root cause of the problem could be anything from a worn spark plug to a costly internal engine concern.
Hence, it’s a good idea to check for technical service bulletins (if you have access) that could help with the troubleshooting process.
Below are a couple of video references you can use to help you perform a diagnosis:
Due to the diversity of vehicle models and the different conditions that can trigger code P0305, there isn’t really a universal solution for this issue—which can make it difficult to address the problem, especially if you’re not an expert.
If you’re confident enough to resolve the P0305 code on your own, make sure to consult the factory repair information to ensure the suitability of your repair approach. Use repair manuals or, better yet, invest in an ALLDATA single-vehicle subscription to expand your technical know-how.
When in doubt, don’t hesitate to reach out to your trusted mechanic. They’ll be able to help you pinpoint the exact cause of the issue and determine the best course of action.
Your ignition system is crucial to the operation of your vehicle. So if your scan tool logged code P0305 due to the ignition issues, it’s best to resolve it immediately. Luckily, it’s easy to find ignition system parts, like spark plugs and coil packs, here at CarParts.com.
You don’t need to leave your home to shop for the parts you need. You can do it on your phone or computer when you shop online at CarParts.com. Visit our website, filter the results to compatible parts using the vehicle selector tool, and make the selection more specific to your needs with the filters. It only takes a few minutes to find and order what you need.
All our products are available at unbeatable prices, so you can get high-quality ignition components without breaking the bank. These ignition components have all undergone strict quality control tests. Plus, our team of industry veterans handpick each part to ensure functionality and durability.
If you have queries about a specific product, our toll-free hotlines are open 24/7. Don’t ignore trouble codes and risk costly repairs. Check out the replacement parts you need, and get back on the road in no time!
Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.