headgasket replaced and now no spark on 2 and 3

[dsmer1]

I had blown my head gasket and replaced it and now there is no spark on cylenders 2 and 3. Both coil packs are good and wires. Replaced the power transistor and nothibg. I think its the CAS or ECU but I don't know how to test the ecu.

 

[robtheturbopric]

most likely its the CAS. if your not sure test it by replacing it with a know good part. but to check the ecu just remove it with the battery disconnected and then remove the metal cover and check for anything burnt or leaking.