Engine cranks but won't start

Have a 99 Ford Taurus with the 3.0 L
Vulcan engine. The serpentine slipped off
while driving a few weeks ago and for
some reason a lot of antifreeze was lost.
After I refilled the antifreeze and put a new
belt on the car will crank but not start.
When I pulled out the spark plugs they
were kinda worn and wet so I replaced
them and it gets spark. Tested fuel
pressure and it's fine as well. But it still
won't start. I noticed that some antifreeze
was leaking out the bottom of the car after
I tried to crank the engine but it looks like
it's coming from the exhaust pipe near the
middle of the car. What would cause that?