Help, 04 GMC 1500 Crew, dual exhaust, no cat, and sucks fuel bad. I need help tuning

[Wyo]

I just got the flashscan v2, I barely know how to hook it up let alone use it but from what I get I prob need to recalibrate the o2 sensors for the unrestricted flow of exhaust. More or less I have 2 stock exhausts with no cat and a straight through muffler. At certain rpms it quite but then when the fuel gets dumped its obnoxious. You can see the raw fuel coming out at WOT.
Can someone direct me to what to do or maybe just a map to try, or some further information.
I've been reading but its going to take little more playing around to even start to get the hang of this.

Like I said,
04 GMC Crew Cab 1500 z71 5.3l LM7 295hp The best mileage I've seen is 13.5 but average 12 on the highway. I fooled the secondary o2's so there no cel light on, but you can tell its dumping massive amounts of fuel.

[Gregs]

Welcome,

-Have you read through all the documentation yet? CalcVET or autoVE/MAF is where you should start. There are stickies on those topics in the forums.
-Do you have a wideband because you're going to need one.

[Wyo]

I'll go over those documents but might take a little while before I can really get it down. I figured I needed a wide band, what do you recommend. We run AEM wide bands on our turbo snowmobiles. Will those work.
Is there a possibility to find just a map for the truck that someone built for just a high flow exhaust, so I can just load it and run, then when I get time I can use the stock map and custom tune to compare as I learn.
Thank you for your help

[joecar]

More info:

A-New-Twist-on-CALC-VE-Table-Computing-the-Entire-VE-Table
CALC-VET-Summary-Notes