I have a Taurus 2001 wagon with 83,000 miles. Less than a year ago, the check engine light camo on. i took it to my mechanic and they replaced the spark plugs, wires, # 1 fuel injector and ignition coil. They also flushed the fuel system. Now my engine light is blinking again and car running rough. I took the car to autozone to read the code and it says the # 1 cylinder is misfiring. How could this happen?