I took my car to autozone because the check engine light lit up. They scanned it and it showed that it was misfiring in # 7. Does that mean that the spark plug is bad or the coil? Should I replace all to avoid the headache of another one going bad? My car is almost at 100,000 so I am going to change the spark plugs. I have a 01 lincoln ls with 98800 miles. Thanks
