Bought a LS Swapped S Blazer codes and no power

[mmulisha84]

I picked this S series Blazer up this weekend and it runs and drives, but the owner didn?t know much about anything the Painless Wire Harness is laying all over and yea it needs some love. Finally got a scanner on it today and it?s showing MAF codes IAT EVAP and a few trans codes.
It?s a 5.3 with truck intake, 700r4 that was behind the 350 it had before the LS. He told me a local dump shop took the computer and removed the cats and stuff and put a performance tune in it. When looking it over I asked why it had a cone filter right to the TB and no MAF. He said he had the tuner remove the MAF cause the MAF he had was bad and didn?t wanna buy one. I?m starting to think that he just had VATS removed lol. It runs good and idles good but out on the road with an open diff I can tell it?s not all there. Computer won?t go into closed loop either.
So what?s everyone?s opinion? Running it speed density would require a tune for the MAF not to be there correct. And any reasons it would seem a little low on power. I mean stock tires on an open diff it should smoke one and only does from a dead stop.

[5FDP]

Not only would the tune require that the MAF be turned off but you'd also need to wire in a separate IAT sensor just to make it run correctly. Otherwise all the fueling is going to off and it thinks the air temp is always -38 degrees.

A whole bunch of other stuff must be turned off if the stock transmission is no longer there. Like trouble codes and abuse modes.

[mmulisha84]

Sounds right lol. Figured the computer is thinking crazy, CTS says 190 IAT says -38 lol. So for starters I should probably just buy HP Tuners, and for starters a CAI or something to install the MAF?