I am using the GUI and no problems
I tell you, the problem lies into "extrapolating" the Voltage/Flow values of the PROM into the EECTuner MAF transfer, seen this many times.
But if you use the stock MAS, then you dont have to deal with voltage changes, just the new flow numbers of the PROM (or any other) MAM housing.
Try this before getting that chip,
1. Install the STOCK sensor on the PROM housing
2. get STOCK MAF table...and multiply the FLOW (dont touch voltage) by percent size increase of MAM.
ProM 75mm / Stock 65mm = 1.153
3. Multiply all the flow numbers by 1.153
4. adjust any rich or lean spots
Go take a spin
