by Trail X » Mon Jan 13, 2014 6:36 pm
Keep in mind this is the 6.0 L v8, not the I6.
The MAF sensor does sound suspect. The engine's gotta know how much air is being pulled into the engine, and if it doesn't, it will fall flat on it's face when you try to give it power. I'd say a rough idle could be a IAB (assuming the LS has one), but since it's falling flat under power, it's probably not that since the air through the IAB is so minimal comparatively at higher throttle inputs.
I'd certainly start with the MAF. Try cleaning it, see if there's a difference. If no difference, try unplugging it, see if there's a difference. If no difference when unplugged, then I would suspect that your sensor crapped out. Might try that same tactic with the intake air temp sensor. Have you checked the O2s? Could be that one of those went bad.
Do you have a Scangauge to help with your troubleshooting? It would make sense to check as many sensors as you can for sensible data. Try making sure the TPS is reporting properly, make sure the IAB is reporting properly, intake temperature, fuel pressure (if reported), closed loop or open loop, a/f ratio, there may even be a way to read raw data from the MAF sensor.