Typical sign of a bad ignition coil is a check engine light and/or rough idle and misfire.
Ignition coils can be expensive and only get replaced when they have failed. Some vehicles have one complete coil system and others have multiple separate ignition coils.
At first a broken coil can be difficult to detect but usually the first symptom is that you will notice a slight misfire which could cause a slight hesitation while accelerating. Typical sign of a bad ignition coil is a check engine light and/or rough idle or bad misfire. The symptoms will get worse as time progresses and then other parts might start failing. The easiest way to determine if the coil is bad is to switch coils with a good one or swap it with a coil that is working on the other cylinders. There is a charge to diagnose a bad ignition coil as it takes time to get to it and determine if it is the root cause of the problem. The ignition coil on a vehicle is an important component that needs to operate correctly or more problems will arise.
Most vehicles have one coil for every two cylinders, however, more have been coming out with one complete coil system for all the cylinders which means when one goes bad we have to replace the entire unit. To change out an ignition coil you first start with disconnecting the batter, then mark and remove the plug wires and then finally remove the coil. Some vehicles require the intake manifold to be removed. Then reverse the order and reinstall the wires. Then most importantly recheck the system.
You can but eventually you will not be able to start the vehicle or get it up to any speed on the road. Plus, at this point you are causing damage to your catalytic converter which is a very expensive component. What occurs is the cylinders with the bad coil are not igniting the fuel so then raw fuel is getting through the system and clogs the cats. Get the coil fixed so as soon as you discover it is damaged, so you won’t get stuck on the road.