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Faulty: spark plug, spark plug wire, ignition coil, ignition module, fuel injector are the most common. Coolant leaking into a cylinder is another. Internal engine problems such as burnt valve, broken valve spring, bent push rod, worn rings
Could be a bum fuel injector. Pull number 6 spark plug again, if it is wet you have a spark problem. If the plug is bone dry you have a fuel problem, probably a bad injector. Swap injector with another cylinder and see if the misfire switches cylinders or remains on number 6 cylinder.
The ignition lock cylinder on a 2006 Chevy Cobalt is removed by popping off the steering column cover and inserting a screwdriver into the release hole. The cylinder can then be pulled from its housing and replaced.
Very possible.
There wasn't a 1991 lhs. If the key will not turn, the cylinder Will need replaced.
Assuming the plugs and wires have already been replaced you may have a bad fuel injector.
did you replaced spark plug also distributor cap and rotor???
CHECK WIRE
It did when new. It should still unless a key cylinder has been replaced.It did when new. It should still unless a key cylinder has been replaced.
Faulty: spark plug, spark plug wire, ignition coil, ignition module, fuel injector are the most common. Coolant leaking into a cylinder is another. Internal engine problems such as burnt valve, broken valve spring, bent push rod, worn rings
If you mean the fuel injector for the #4 cylinder isn't working the answer is simple, either the injector is bad and needs replaced, or the connector has gone bad/ the wires are shorted out. Put an injector pulse tester on that injector (most people don't have these so you'll need to get it tested at a garage), if the injector doesn't fire when it's tested separatly you need an injector. If it does fire that means the plug/wire is the problem.
Wire , lots and lots of wiring , but you need to be more specific , a Echo uses 4 coils , 1 for each cylinder , and being a mechanic myself at a Toyota dealership , this is rare. Make sure your not having condensation problems , ex water around the coils , as this will cause arcing and it will look like the coil is not delivering its spark.