Cel keeps coming on. 1st dealer gets misfire codes on 3 and 4. Says could be after market plugs so changes them to. Subaru plugs. 150 miles down road cel on again. Next Subaru dealer another 650 miles road. Misfire code on 3 and 4. Couldn't find anything, drives fine, reset codes. 500 miles down road cel on again. Next Subaru dealer misfire code on 1, 3, and 4. Says valves need adjusting. Getting very frustrated with non definitive solutions which keep costing more money. I am out 360 for spark plug replacement which was obviously not needed since it did not fix the problem…
If the spark plugs hadn’t been changed until 130k, it was time for the to be replaced anyway. This is probably why the dealer went with that repair as worn spark plugs can cause misfires. Ignition coils are another part that may fail and cause misfires when they malfunction. A compression test and cylinder leak-down test will show if there is a problem with the valves. You can try having the coils replaced and the valves adjusted by the dealer. Consider hiring an experienced technician like one from YourMechanic who can come out and conduct the same tests as the dealer could and determine the cause for your check engine light.
How to Identify and Fix Common car Problems ?
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You might get a misfire code after spark plug replacement for an individual cylinder like a P0303. The code indicates a misfire in cylinder three. Sometimes the spark plug is dropped, and the ground electrode and the center electrode can make contact. Or the problem could be with the connection to the coil.
After you`ve changed your spark plugs, you should start up your engine to make sure they`re working as they should. If your engine starts up without a hitch, you can pat yourself on the back for a job done right.
What does code P0300 mean? The P0300 engine code indicates a misfiring cylinder problem in your vehicle. The misfiring happens when insufficient fuel is burned or when the spark plug gets damaged. In addition, it can damage your car`s catalytic converter in extreme conditions.
In most cases, successfully repairing the issue that caused your light to come on will cause the check engine light to turn off automatically—but only after 10 to 20 “cycles”.
A clogged or failed exhaust gas recirculation or crankcase ventilation valve or faulty oxygen sensor can send the wrong signals to the computer and cause misfires.
bad spark plugs can cause your engine to misfire. the engine`s computer uses sensors to detect these misfires and will create a code that turns on the check engine light. a flashing check engine light indicates the misfire is severe enough to cause damage to your catalytic converter.
A spark plug usually lasts about 30,000 miles, but cleaning them and maintaining them periodically lets your engine perform better and increases your plugs` lifespan. If you see rust, carbon, gunk, dust, or any type of buildup during the inspection, it may be time to clean them.
No reset. You can reset adaptions but that isn`t necessary.
No, replacing the spark plugs will not turn off the check engine light. You have to have a scan tool or a code reader to clear codes. It may be that a bad spark plug was causing a misfire code, but the code doesn`t go away until it cleared from memory with a scan tool.
The most common causes of misfires are worn, improperly installed, and mishandled spark plugs, malfunctioning ignition coils, carbon tracking, faulty spark plug wires and vacuum leaks.
In a very similar vein to the above point, spark plugs that are worn, dirty or simply too old to work properly can cause your engine to occasionally misfire. Engine misfires will halt your entire vehicle for a second or so and create a loud noise similar to a gunshot out of your muffler.
Our advice: P0300 (when misfiring occurs in random or multiple cylinders) is bad. A misfire is a very serious problem for an engine to have. If you see this fault code you should stop driving immediately, figure out what is causing the trouble code, and fix it.
The reasons for a check engine light turning on can range from something minor like a loose gas cap to something more serious like a faulty catalytic converter. It could even be a sign of internal engine failure. Ignoring the problem can turn a potentially quick fix into a costly and time-consuming repair.
The Light Stays On
If you`re experiencing this, don`t panic. You may think that there is still a problem with the car after the repair, but it`s because the light needs time to reset. The car`s internal computer only resets after a set period where it checks all of its sensors once more.
Oxygen sensors are a common cause of “check engine” lights. This sensor is located in the emission control system of your car, and is standard on all vehicles manufactured after 1980. The oxygen sensors are used to ensure that your engine is burning the correct amount of fuel, and running at peak performance.
While the check engine light can definitely be indicative of serious problems, the most common cause of the flashing is usually an engine misfire. There are many reasons why an engine misfire might be occurring. To run smoothly, an engine must be receiving the correct amount of power from the cylinders in your vehicle.
A flashing check engine light indicates a much more serious issue. Most often it means that the engine is misfiring and unburned fuel is getting into the exhaust system. This raises the temperature of the catalytic converter and can cause critical damage.
A blinking check engine light will show up on your dashboard is almost always correlated with engine misfires. A misfire means that the engine is dumping uncombusted fuel into your car`s exhaust system. Engine misfire is a serious issue because it can quickly raise the temperature of the catalytic converter.
What a Blinking Light Means. It could be overheating or an oil pressure issue. It could also be a problem with the brakes or fuel line, belt, hoses, etc. By far, though, the most common is a misfire in the engine that can damage the catalytic converter.
