engine code p1703?? is it easy to fix

thanks hyundaitech once again.this car wont stop taking my money!!!we
maintenace the car very good.went to the dealer bought the sp111 fluid
pour some in the trans.but the car in reverse an it start to move but not
so fast.when backing up the engine rattles when i let go of the gas
pedal.i dont know if its to late drove the car for a week with low fluid
it was about 1 half qrts.low.in the morning when i start the car put it in
reverse it moves normal?but after the engine is warm its back having the
same problem weak reverse.and when on the road driving when when i look at
the rpm at 3000 rpm it change rough on 3 gear.all other gear change below
3000 rpm.i drove the car with the engine light for 2 years.and it never
did the rough change gear.till now! i got 3 engine code (1703) transfer
box line fault open circuit short fault.this right?and what does it
mean?is it easy to fix?code(p1123)long term fuel/trim multiplicative
system lean?how to fix this?code(po422) 02 sensor main catalyst efficiency
blew threshold (bank1)is this right? were to start fixing the problem?more
money out of my pocket!!going broke.hey hyundaitech you should be
chargeing us for your good advice.thanks

 

P0422 means your catalyst is inefficient. If both your oxygen sensors are
working properly, you'll need a new catalytic converter. Be sure to check
for any exhaust leaks. If your front pipe or manifold is leaking, the
oxygen sensors can't work properly.

P1123 indicates your PCM is delivering significantly less fuel than it
thinks the engine should need based on the input from the oxygen sensors,
the mass air flow sensor, the crankshaft sensor (engine speed) and the
throttle position sensor. This could be due to an injector leaking into
the cylinder, excessive fuel pressure, anything which would cause the fuel
to go unburned in the combustion chamber (misfire), or a misreading sensor.
This is likely the toughest of your problems to isolate.

P1703 represents the transmission computer believing the throttle position
sensor is out of specification.

Your car was made around the time Hyundai was having some throttle
position sensor issues. I'd start by replacing the throttle position
sensor. It can be affecting your transmission operation, but based on
your descriptions, I hesitate to express confidence it will repair all
your transmission problems. You could be looking at a major transmission
repair. If this fixes your transmission issues, I'd then look for an
exhaust leak and repair any leaks found. If there are none, you'll need
to address the P1123 issue and figure out whether your oxygen sensors are
working properly. If so, you'll need a new catalytic converter (based on
P0422). If I recall correctly, the main catalytic converter on your car
is part of the exhaust manifold. In any event, if you're replacing a
converter, you'll need to replace the one between the two oxygen sensors.