My car has started acting very strangely. The acceleration is jumpy when low RPMs, when in reverse, and there's power loss. The car vibrates when it idles and the exhaust sounds are erratic instead of smooth. I've replaced the spark plugs, but that didn't help. What should I do next?
The ignition system has more than just spark plugs, and some of the other parts, like the plug boots or the coils, are causing the misfire and running rough.
I would remove and inspect the plug boots and coils for any signs of causing the misfire. They would show signs like carbon tracking or cracks in the coils.