you're correct.. roughly between +1.0 and -1.0 should be seen...
Just a few questions:
- Was the diag/engine light illuminated by any chance?
- What is the mileage on the car?
- Is it remapped ?
- Any work done to the engine recently?
- Is it consuming more fluids than usual?
- Are the values on the excel files taken at idle? (Kinda looks like they are)
- Using the FIAT ecu scan, how did all the other values look, like air temp and coolant temperature?
I'm guessing the 'firing order' is 1-3-4-2... any expert here confirm this? If so it looks like cylinder 1 and 3 are totally out of phase with respect to each other, and the magnitude of the corrections are nearly double that of 2 & 4....hmmmm
If it were my car I'd do the following:
- Check the neg terminal on your battery! Is your battery ok??
- Disconnect the airflow meter does that improve the engine idle..
- Have a compression check done.
Worst case it could be dodgy injector(s).. that's a specialist work.. they may need to be cleaned, testing and calibrated on a test bench. (don't know of a business in your area).
Sorry can't be more helpful.....