[thstone]

You need four items to make a car driveable;

1. Key fob with internal transmitter
2. Immobilizer (under seat)
3. ECU (rear trunk)
4. Key shank to match the lock

1-2-3 must be electronically matched (coded). If not, then the car won't start.

If 1-2-3 are not coded the same, then you need a dealer or a select indy who has a PIWIS or PST2 who can re-program them all to match.

Of course, the key internal transmitter (#1) and #4 can be swapped around between key fobs as desired (just open the key fob and swap away).

You say: "I found a set that has keys,ignition switch,immobilizer and some small box electrical part". If the "some small box electical part" is the ECU, then you should have a matching set that should get your car running. If that small box part isn't the ECU, then you'll have to go to a dealer/indy to have the new key transmitter and immobilizer programmed to match the existing ECU in your car.