I've got a 2002 with a 4.2 motor. Last Nov. it started to miss and lost power. I changed the coil pack, Plugs,and Wires. It ran good for about 2 months then the miss came back. I put new plugs (Motorcraft) back in and it ran great. After about a month the miss is back. I've changed the wires and coil pack again but it didn't help. I don't want to keep changing plugs every month. Has anyone run into this before? If so what did You do to fix it . Thanks Scott

 

What did the plugs look like?

 

4 are light tan, 2 are a little bit darker. I had Auto Zone scan it and #3 and #4 plugs were missing, the same ones that are darker.