My 01 Hoe with 95K miles is going out. Last 20K miles its gotten louder. It pings under hard throttle and feels gutless at WOT. I scanned it last month adn its LTRIM values were over +20.

 

It's not a GM truck, but on my other car, an 87 Fox body 5.0, I changed the fuel pump last week for the same reason. I never heard it running before and then all of a sudden, BZZZZZZZ I hear it in the car while I'm driving. I am kinda hard of hearing so instead of taking any chances I changed it when I could.

I can't even hear the new one, even during the 2 second prime when I turn the key on. It was less than $120 for a fuel pump and strainer. Edit to add that the car has 95,xxx miles on her now.