Code P0743 is a code relating to the torque converter. Possible causes are a faulty torque converter solenoid, poor connections, wiring problems, or a faulty computer. Most likely here is a faulty solenoid. Before replacing parts, clear the code and see if it returns. This may be an intermittent problems.
If the code returns,
1. Test the resistance of the torque converter clutch solenoid, normal is approximately 30 ohms. Replace the solenoid if open or shorted. 2. Check for voltage on the Dark Blue/White wire at the Torque Converter Clutch (TCC) connector. 3. If OK, do an actuator test with the scanner. 4. Connect a test light across the two wires in the TCC connector to see if the Powertrain Control Module (PCM) is pulsing the driver to ground. 5. If the actuator test does not pulse the test light, the driver in the PCM may be faulty or a problem in the wire between the connector and the PCM. 6. Check the wire for an open circuit, a short to ground or a short to power.
Code p0140 is an O2 sensor code. The sensor after the converter. First, verify there is no exhaust leaks. Check the power on the Dark Green/Orange and ground on the Black/Light Blue and Black wires at the O2 Sensor with the engine running and the sensor plugged in. If no power, check your fuses or wiring problems. If no ground, add a ground as the wiring is likely faulty. If all is good, you likely have a faulty sensor.
As for your back up lights... First, check your fuses. If fuses are good, check your bulbs. If that is good, you likely have a bad backup light switch.