WAM, since you have a 05 you have either a IAT1 or a MAF (which also contains a IAT1) I've included a picture of the 05 running change that is a IAT1 only( does yours look like this) if it does look like the setup in the picture then you only have a IAT1 (intake air tempature sensor 1) and the ECM may only show 4G/s at all times. Now if you have a 6 wire MAF sensor then your G/s readings can be 30G/s idle and over 350G/s during WOT on a stock truck. Mine personally read 31-32G/s idle and upto 440G/s WOT. In the old Strategys MAF was only used for EGR operation but with the newer strategys an increased importance in placed on MAF as it's used along with MAP, BARO, EOT to inferre EBP. also MAF is used in comparison calculations against MAP to make sure things are within limits. If one uses a oil based filter and a newer inferred strategy it's always good to make sure your MAF sensor is clean. I use electrical contact cleaner to clean mine every year so to keep the oil film off. One of the reasons Ford brought the MAF back in 06 was due to newer inferred strategys and it's importance of use. well thats just my two cents of what I've learned researching this over time and a may have missed a few tidbits.