Will bad spark plugs make a car smoke out the tailpipe?

Yes, bad spark plugs can cause a car to smoke out the tailpipe. When spark plugs are not firing properly, they can cause the engine to run rich, which means that there is too much fuel being injected into the cylinders. This can lead to incomplete combustion, which produces smoke. Additionally, bad spark plugs can also cause the engine to misfire, which can also lead to smoke production.