2007 Yaris wont start --Help!

[veedubbed]

I have a 07 yaris automatic that was told had a bad ECU and wiring harness on it. I have replaced both. I am getting plently of fuel and spark but the car still wont start. Any ideas?

[CTScott]

What's the part number of the ECM that you purchased? It may be one that has the engine immobilizer.