1998 Accent Problems

I took my '98 Accent to Autozone to have the check engine light checked.
These are the codes that came up:

P0447 - "The PCM has determined that a open circuit condition exists in
the electrical circuit for the vent control in the evaporative emission
control system." A friend of mine that's familiar with cars told me it
was the gas cap and not to worry about it. Another told me it might be a
hose that's leaking/torn.

P0733 - "The PCM has detected an incorrect gear ratio condition in 3rd
gear."

P0717 - "The PCM has determined that there is no input voltage signal
from the turbine speed sensor."

P0722 - "The PCM has determined that there is no voltage signal from the
output speed sensor."

One code didn't have an explaination - P1614.

Does anyone know anything about these codes? I would REALLY appreciate
anything you can tell me.

Thanks.

P0447 is strictly an electrical circuit code. You should look for damaged
wiring in the neighborhood of the charcoal canister and check to see
whether the close valve (this will be the electrical device attached to
the canister) is plugged in.

P1614 means that the transmission computer has requested a check engine
lamp. See P07xx below.

P0717 and P0722 are for incorrect or no signal from your transmission
input and output speed sensors. They come together as an assembly and are
called pulse generators. There are known issues with these. Replace them
and check the wiring in the vicinity.

P0733 means that the transmission is "slipping" in 3rd gear. The
computer's ability to determine this is dependent on proper operation of
the pulse generators, so don't even try to address this code unless you've
cleared the codes, made the repairs for P0717 and P0722, and the P0733 came
back but the others did not.