Welcome to CEG!
Gap is .051 not .54 (over a half inch
)
You do need to replace that valve cover gasket. Some oil made it into the cylinders causing the smoke and oil will ruin the plug boots.
It would also be a good idea to replace the timing belt now.
Beware of the known timing belt instalation problem on Zetec engines with VTC.
Has your CEL come on, or have you had codes pulled?
Did you put in acceptable replacement double plat plugs?
How do you know the CATs are fine (both)?
Go ahead and replace the plug wires with OEM or Ford Motorsport. You may well have caused damage to an electrode end when replacing the plugs. Double check that the plugs are of proper type and are secure (not stripped or leaking cylinder pressure) Check for vacuum and intake leaks too.
Mileage that poor should trigger a CEL, make sure the light actually comes on when the key is turned to the run position. Codes will make further diagnosis easier.
If you still have any problems let us know.
