An engine misfire is never a good thing for a vehicle. If any of the engine cylinders do not have enough fuel to burn, then it will cause a misfire in that cylinder. The engine may still run and produce power, but it won’t be enough power to satisfy the demands of the acceleration pedal. A misfire only needs to happen in one cylinder for the engine to experience power problems.
Aside from weak engine power, a cylinder misfire will cause other symptoms too. Some of the symptoms include a fuel odor in the exhaust fumes, rough running engine, shaking / vibrations, and/or the Check Engine warning light turns on. When you experience one or more of these symptoms, run a diagnostic scan on the powertrain control module. If you receive trouble code P0305, then it means a misfire was detected in Cylinder 5.
There are several possible reasons for a misfire to occur in Cylinder 5. You may have a bad ignition system, internal engine issues, fuel system problems, bad spark plugs, bad spark plug coils / wires, vacuum leak, bad fuel injector, bad crankshaft sensor, bad camshaft sensor, head gasket leak, timing of engine is off, bad fuel quality, low engine compression, and bad quality fuel.
Whenever you have a misfire in any of your engine cylinders, you need to take it seriously because it is a very big deal. If you simply ignore the misfire problem by failing to get it fixed, then other major components of your vehicle are at risk of getting damaged. You may end up with a damaged catalytic converter, ignition, or engine.
Furthermore, you’ll find it quite difficult to operate your vehicle when it has a cylinder misfire. The acceleration will seem slow and sluggish, which means highway driving is out of the question. You may end up risking the lives of other people on the road as well as your own life if you drive under these conditions.
Therefore, do everyone a favor and have a professional mechanic repair or replace whichever component or system caused the cylinder misfire in the first place.