ses light on, ticking noise in engine & engine shakes at low speeds & idle.
 

All of these problems started all at once while driving with no warning signs at all. Oil had been changed 3 weeks ago. Went and had diagnostic test done, came up with code 300. Ive heard everything from nothing major maybe spark plugs & wires to you have a broken piston & engine is totaled...... my dealership/repair is a 40 min drive away, is it safe to drive? Any help is appreciated!!

Btw....it is a 2004 :)

So I got it to the dealership......engine is shot :( is it even worth it to put a rebuilt one in it? It has almost 160,000 mlies on it. Im just not sure I want to put another $2000 into it, we just paid $4000 for it 2 months ago. Should I just cut my losses?

$4000 is a hefty bit of change. I don't think my minivan is worth it, but if the body is near-perfect and nothing else is wrong with it, it may be worth it. Sorry to hear about that. I hope the last owner wasn't aware of it.