How to Megasquirt your 3G Hemi
Also, you need to calibrate your O2 sensor using:
Tools > Un / Lock > unlock calibration settings
Tools > Calibrate AFR > Pick EGO Sensor (Innovate LC-1 for me)
You can also calibrate your thermistor tables, but if you're running GM sensors, you don't have to.
Make sure you lock your calibration settings after you finish those above.
Then, calibrate your Throttle position sensor (tools > calibrate TPS), and your MAP sensor (tools > calibrate MAP). Fairly straightforward. You need to get a reading with your TPS fully closed, and fully open. Also, you need to know what MAP sensor you have!!!