2007 Toyota Camry 2.4L please help
 

I bought a 07 Toyota Camry 2.4L a few weeks ago and the last owner replaced the engine and tranny and harness and the ecm from a 2011 Toyota Camry 2.4L because the motor had a rod that was broken. He replaced it and now it won't start, cranks but no start. He told me that the Immobilizer had to be replaced. NEEP HELP PLEASE