I've seen it been called both, but is there some way to tell if your's has gone bad?? (Besides the obvious way, which would be to replace the ECU completely of course)

 

What is the symptom? You can jump the ALDL terminals to try to retrieve any codes, a flashing 12 will indicate there is a least communication between the prom and the cpu in the ECM. They are very reliable and seldom fail. Most diagnosed ECM's by home mechanics are not the problem.

 

well I had some errors, the one that bothers me is the code 33 which is low vaccuum at the MAP sensor. So I played with wires and I messed with the vaccuum line and nothing.. SO I even replaced the MAP sensor. The error went away after more playing with the wires and the vaccuum line on the new MAP sensor.
The real problem is: I just swapped a 350 into my car, it was a 5.0. I did get the new chip and all that fun stuff.
The car runs like crap though, and it is very sluggish, it has huge power loss on any hill, it stalls when the air is on, and it is so rough in idle. I've tried the car with the 305 chip and the caprice 350 chip (the one for the engine) and it's acted no different. The car still is bad. I even tried numerous new chips. My thought is, that it might be possible that the ECU isn't working correctly and it's falling back to the engine settings that it trys to do whatever it can to make the engine work (thus being why I'm getting 9 miles to the gallon on a highway and all that stuff)
I've already timed the car and that didn't help at all either..
Any clues?
If I dont' figure something out by tomarrow on friday in the morning it's going to the dealer.. I hope it doesn't set me back TOO much....

 

Make sure your wiring to your sensors and injectors is reaching the ECM. It may not have the knock sensor input, which would retard the timing 20*. Or, it may only fire on 1 injector.