I have an 07 f150 4.6. Just bought the truck. It was running great till a coil went bad,#7. I swapped out the coil and it ran great. About two weeks after it misfire again. Gave me the cylinder 7 misfire code. I replaced all the coils and spark plugs, for the exception of 1 coil,1 spark plug cylinder 2.(Motocraft) the ones I didn't change has a rounded bolt head. While doing so I also removed the fuel line on bank 1 to get to a coil bolt. After starting her back up I noticed significant mpg loss, rough idling, and slight power loss. Today the check engine light came back on. And this time it gave me p0053-heater resistance b1 s1 twice. P0133-o2 circuit slow responseb1s1, and p2195 lack of o2 sensor switching, too lean.b1s1. I noticed that that particular sensor is on the side of the fuel rail I removed and coil/spark plug that stayed the same. Could that be an issue?and why? I was going to replace the o2 sensor but the one in question looks brand new, a bosch. Any suggestions would help. Thanks