It lurches when N to D and also doesn't shift smooth at all.

Question

there are times when it's in D and the engines revs like it's in N.
I just changed the fluid with PIII that I bought at the hyundai dealer.
the fluid level is good when engine is hot and the tranny is in N.
When I start the engine, it revs steady at 2500-3000 rpm for 3 or 4 mins before dropping to normal. The outdoor temp is only 60 degrees and the battery is fully charged when this has been happening.

Answer 1

P0123 Throttle position sensor circuit high input

P0138 H02S circuit high input (Bank 1 Sensor 2)

The throttle position sensor is a important signal, to the TCM (transmission control module) Because the TPS is circuit high or faulty you can expect a mistimed shift, you will need to replace the TPS to correct the condition. As for P0138 this is the downstream 02 sensor or the catalytic monitor sensor, a worn downstream 02 sensor is usually indicated by a circuit high input condition