Code 66 + maf install

I put a new maf on my car, suppossedly a 70mm 19lb calibrated unit. I put it on and it runs horrid, surges, sputters, nearly dies. I fiddled with the scanner and after coaxing it out, a 66 spits out, saying MAF voltage is too low basically. Whats the problem? Is this pos no good or is it a bigger maf? I bought it from classifieds so it's not store box new.

The part # off the maf is FORD: F1ZF-12B579-AAAFH55-03B

Nevermind, figured it out. I put the maf bracket on and fought with it to get it on this time and it surged twice then ran without anymore trouble. Nice little power gain too I think. Either that or the cooler air one.

Yeah its a ford maf sensor I assume since it has a ford logo stamped on the plastic piece on top with ford looking part #.

My only guess on the issue is that when I first done the install and didn't do the bracket (since it was a pain to get back in, and I heard you didn't need it) that either it was turned at a weird angle, or since the rubber tubing couldn't hold the weight of the maf, it bent down and leaked air or something. I really don't know. All I know is I just thought I would try it again, but this time try the bracket since I remembered reading one time the angle of the sensor was kinda picky, so I slapped the bracket back on it. Fired it up, surged twice then went to a normal idle. Check engine light never came back on, took it out, played with it, etc. Went WOT and felt a little gain there. Now I can't wait to see what my intake and throttle body will do. Lol, then the h/c and suspension to follow that. I still gotta learn to tune though, but I bought a book that was reccommended several times on this site called "ford fuel injection & electronic engine control", and a white gt with blue stripes on the cover.