I have a 2013 Sonata 2.4L L4 DOHC 16V SE Auto. Can replace this engine and transmission with a 2.0L L4 DOHC 16V engine and what other compnents will i need to change as well from the 2.0 car??

well you might want to snap up the ECU and all injection related components including ALL ignition systems from the donor vehicle...really, chap...unless you've got clear garage space and skads of time to perform this would advise against it with THESE cars...which are NOT Toyotas~

Roy, Thanks for the advice. Very correct to note that these cars are NOT Toyotas. Its been pretty difficult to get a good enough deal for the exact 2.4L replacement. But I just got a great offer for a 2.0L car accidented from the rear. So i'm thinking about giving it a try, hence the need for expert advice. I have free access to anything i want to take from the 2.0L car. As for time, i'm thinking that it wont take too much extra time as we would need to do an exact replacement. What do you think??