P03044 Mercury -

Question

My engine light is on and it is running ruff

Answer 1

Hi there,

The engine is running rough because of a misfire on cylinder #4. That's the P0304 code. This is usually due to a faulty spark plug or ignition coil.
Read more here:
https://www.autocodes.com/p0304_ford.html

The P0442 is an emissions code for a small leak, there can be several reasons for it such as a loose fuel cap.
https://www.autocodes.com/p0304_ford.html