So by the title you can see I bought an 07 Taurus. I paid $1100 for 113k miles and took it to a repair shop for an estimate. Apparently the cat is bad which I knew, but the codes say cylinders 4,5, and 6 are misfiring. Also the car is saying it's running rich and lean at the same time. Also, the car idles very rough, jumping rpms randomly. I was told it was probably the pcm by the mechanic and a family friend said the cat can cause a lot if those issues, does anyone know what's wrong?