heres how kia checks the 734 code
Diagnostic Trouble Code Diagnosis Charts
P0731, P0732, P0733 & P0734
Gear 1, 2, 3 and 4 - incorrect ratio
Threshold Value ~
Ration of vehicle speed (calculated from input speed and gear ratio) / vehicle speed from meter set: > .62 MPH
Enable Conditions ~ Range switch: In D, 2 or 1
Time Requirements ~ Continuous
MIL Illumination ~ 2 driving cycles
Related Items
Low ATF level.
Low Line Pressure.
Internal transmission malfunction.
Shift solenoid stuck open or closed.
Faulty Linear Solenoid Valve.

If any of the following codes (or pending codes) are present, do ALL repairs associated with them before proceeding with this troubleshooting tree:
P0712 or P0713 (Trans Fluid Temp Sensor).
P0716 or P0717 (Input/Turbine Speed Sensor).
P0748 (Linear Solenoid Valve Electrical).
P1500 (Vehicle Speed Sensor).
P0753, P0758 or P0763 (Shift Solenoid Electrical).
STEP
INSPECTION
Y/N
ACTION
1
Check ATF level (transmission at normal operating temperature).
Is ATF level low?
YES
Check for any signs of leakage from transmission. Repair as necessary and fill transmission to full level.
NO
Go to step 2.
2
Check ATF condition and compare to following chart.
Clear reddish pink: Normal condition.
Dark or black (with friction material): Internal transmission malfunction or excessive wear.
Milky pink: Water contamination.
Light to dark brown (oxidized): Overheated or worn out fluid.
Is fluid condition other than normal?
YES
For ATF condition #2, replace transmission.
For ATF condition #3, replace fluid, repair source of contamination and perform pressure tests. If water contamination is severe, replace transmission.
For ATF condition #4, replace fluid and perform pressure tests.
NO
Go to step 3.
3
Following is a list of some symptoms associated with stuck open or closed shift solenoids. Compare code and/or symptom to vehicle to determine if a solenoid malfunction is at fault (A stuck open or closed solenoid may cause multiple codes – the following are the most likely to occur).
Stuck Closed:
A - P0734 ~ No second gear.
B - P0731 ~ Starts out in 3rd gear.
C - P0734 ~ May have some surging present in 2nd gear. Slight flair and then abrupt relatively hard 2-3 shift.
Stuck Open:
A - P0731 ~ Starts out in 3rd gear.
B - P0733, P0734 ~ False neutral at 2-3 shift.
No 3rd gear.
C - P0733 ~ Early 1-2 shift. No 3rd gear.
Do any symptoms match the vehicle?
YES
Remove valve body and, check solenoids for proper operation (normally closed, open when energized). Repair as necessary and perform steps 4 and 5.

Check Line Pressure Solenoid Valve along with Shift Solenoids before reinstalling valve body into transmission.
NO
Go to step 4.
4
Check line pressure per Service Manual (section 42) and compare to the following chart.
Line pressure
Idle
1, 2 and D : 57-128 psi
R : 71-142 psi
Stall
1, 2 and D : 114-185 psi
R : 71-142 psi 200-270 psi
Is line pressure within specification?
YES
Go to step 5.
NO
If pressures are consistently low, remove line Pressure Solenoid Valve from valve body and check operation (normally closed, open energized). If Line Pressure Solenoid Valve is okay, replace transmission.
5
Check stall speed per Service Manual (section 42) and compare to following specification:
Stall Speed: 2200~2500 rpm.
Is Stall Speed within specification?
YES
Thoroughly check for loose, bent or corroded connections from Vehicle Speed Sensor to TCM (refer to P1500 troubleshooting tree for schematic), Input/Turbine Speed Sensor to TCM and C145 to TCM..
NO
Replace Transmission.
6
Clear codes and return vehicle to original condition. Verify any repairs by driving vehicle with KIA Data Pro connected to OBD-II connector and monitoring for pending codes (refer to section 3 of the KIA Data Pro Generic OBD-II Program Card reference manual).
And for the 422
Diagnostic Trouble Code Diagnosis Charts
P0422
Main catalyst efficiency below threshold
Threshold Value ~ Quality factor (AHKAT) ~
Manual trans: > 0.65
Auto trans: > 0.70
Enable Conditions ~
Engine speed: Between 720 and 2520 RPM
Load value: Within pre-determined map criteria
Calculated Catalyst temperature: > 738 degrees F
Catalyst load: Within pre-determined map criteria
Fuel system status: Closed loop
Time Requirements ~ Continuous (> 100 seconds)
MIL Illumination ~ 2 driving cycles
Related Items

Catalytic Converter deteriorated.

If any codes relating to O2 Sensor, MAF Sensor, injectors, a P0171 or a P0172 are present, do ALL REPAIRS associated with them before proceeding with this troubleshooting tree.
Connect KIA Data Pro to OBD-II connector and proceed to screen for User Data List for ECM. Switch O2S B1 S1 and O2S B1 S2 to YES and leave all others at NO (press enter). While monitoring O2 Sensor voltages, press F5 to access graph of data. Press left arrow once to lower graph time to 15 seconds. Allow engine to idle and stabilize at operating temperature. Graph should be similar to the sample on the left, though the exact amplitudes and switching times will be different. The main criteria to look at is the bottom graph (Rear O2 Sensor) should be very flat compared to the top graph (Front O2 Sensor) as in the sample on the left. The sample on the right is a worst-case-scenario. It represents a completely burned out Catalytic Converter (Cat).
A weak Cat will have a lower Rear O2 Sensor amplitude, but will mimic the Front O2 Sensor in appearance. Replace Cat if O2 Sensor graphs indicate it is deteriorated. If Front O2 sensor voltages are consistently high, or freeze frame data shows an excessively high negative long fuel trim, check fuel pressures and injectors per steps 1 and 2. If Front O2 Sensor voltages are consistently low, or freeze frame data shows an excessively high positive long fuel trim, check fuel pressures and injectors per steps 1 and 2. Also check all vacuum hoses and intake for vacuum leaks per inspections in steps 3 and 4. Make sure there are no exhaust leaks which could dilute the rear O2 sensor readings by performing inspection per step 5. Recheck O2 Sensor operation after completing repairs while test driving vehicle. Verify the vehicle is not running in an overly rich condition as this will burn out a Cat.
STEP
INSPECTION
Y/N
ACTION
1
Refer to Service Manual for proper test procedures and precautions before doing any fuel pressure tests.
Perform Fuel Pressure Test (46 to 51 PSI).
Perform Maximum Fuel Pressure Test (65 to 94 PSI).
Perform Fuel Pressure Hold Test (25 PSI minimum after 15 minutes).
Are fuel pressure tests within specifications?
YES
Go to step 2.
NO
Repair as necessary.
2
Perform Fuel Injector Inspection and Volume Test per Service Manual.
Are fuel injectors working okay and dispensing proper volume?
YES
Go to step 3.
NO
Repair as necessary.
3
Check for any split, disconnected or perforated vacuum hoses.
Also, check PCV valve for proper operation and Purge Solenoid Valve (PSV) for proper installation and operation.
Are vacuum hoses, PCV and PSV okay?
YES
Go to step 4.
NO
Replace faulty vacuum hose(s), PCV or PSV.
4
Start engine and allow to warm up to operating temperature. With engine idling, monitor Front O2 Sensor voltage or graph and perform the following test:
In short spurts, spray aerosol carb cleaner in the following areas while looking for a long rise in voltage at Front O2 Sensor (a rise in voltage that is approximately as long as the spray of carb cleaner indicates some of the carb cleaner was drawn into the intake chamber richening the fuel mixture verifying a leak). Allow enough time between areas checked for carb spray to dissipate.
Do not spray carb cleaner on or near coils or plug wires. An arcing wire or coil could start a fire!
Throttle body gasket
Gasket between intake manifold and cylinder head
Gasket between intake manifold and surge tank
Seals between intake manifold and fuel injectors
Seal between surge tank and PCV pipe
Are any air leaks indicated?
YES
Repair as necessary.
NO
Go to step 5.
5
Check for exhaust leaks by having a helper hold a wadded rag against tailpipe and listen for exhaust leaks between main catalytic converter and cylinder head with vehicle running.
Are any exhaust leaks detected?
YES
Repair as necessary.
NO
Go to step 6.
6
Clear codes and return vehicle to original condition. Verify any repairs by driving vehicle with KIA Data Pro connected to OBD-II connector and monitoring for pending codes (refer to section 3 of the KIA Data Pro Generic OBD-II Program Card reference manual).