at high rpm I lost power and the engine light started flashing.

I have a 03 5.3 ext cab LS with 109k. Today i was on the highway had to punch it to get around traffic, at high rpm I lost power and the engine light started flashing. Later that day I was driving and got on it again same thing happened. Then on my way back it just started missing out like crazy on normal throttle and the engine light was flashing again, at stop lights it was trying to die. I went to a parts store and ran codes, got MAS code and random misfiring code. So in the parking lot I replaced the $80 MAS. Didn't change a thing, cleared the codes and let it run till the light came back on. This time it was only random misfiring code. So I limp it home, then check plugs and wires. They were original and had planned on changing them any way, but now only had plug money. New plugs didn't help. Well I continued to investigate, Noticed a noise that kinda sounded like a diesel engine from the center of the engine, used to only make this noise when it was cold. I sprayed carb cleaner all over the intake looking for leaks. No luck there. Please help! Need my truck for work. PS I recently replaced the door speakers, not a bose system so I don't think this maters but I don't know. Anyway yesterday got in my truck and the radio wasn't working. Could change stations but no other buttons worked and no volume. Later it was back and working fine, but the clock reset. No probs since.

Answer:
It sounds that you have a faulty fuel pump.
I will try to describe what is happening:
Your fuel pump may work and supply some fuel to the fuel injectors, but does not create enough fuel pressure. That means that your engine is starving for fuel .
If the engine does not get enough fuel, it starts missing and a detonation may occur ("a noise that kinda sounded like a diesal engine ").
You should have your fuel system pressure checked. It should be around 55-62 PSI.
PS. I would reinstall the original MAF sensor if the new one is not a GM's part.
A MAF related trouble code could have been a consequence of the throttle plate opening without RPM increase.