This is my first Miata. Purchased it locally from it's second owner just 2 months ago. Only had 54,000 miles, so I figured it was barely broken in. The previous owner said he had just replaced the catalytic converter. After about 2 weeks, I noticed rough idling when first starting the engine. Then the CEL came on with "random misfire". Cleared the code and thought all was well. A few days later...happened again. After several repeat performances, there was a very bad episode were the CEL started flashing and the car could barely move itself. Now there is a very bad rattle coming from the exhaust and when you bang on the converter, it sounds like there is a big rock loose on the inside. From all the reports I've read I think it needs a new coil pack. The previous owner replaced the crankshaft position sensor and installed new NGK plugs and wires before the new converter. I have purchased a new coil pack and will soon attempt to replace the old one.
Does anyone think this is my best option?