This has happened 2 times today truck seems to be acting sluggish too, I put 93 gas in today I did drive it waaaaay down on the low fuel light before hand any ideas maybe a plugged injector? Trucks a 2004 Denali Yukon thanks in advance

 

It's very common for moisture to get into the knock sensor valleys causing the knock sensor(s) to fail, there is actually a TSB in reference to this. The usual repair requires 2 new knock sensors, knock sensor sub-harness, intake manifold gaskets, and RTV. Upon installation of the new knock sensors and sub-harness, you'll want to build a dam of RTV around the rubber knock sensor connector boots to prevent further water intrusion. If you search the gm section for "knock sensor" you'll find pics of what I'm talking about

 

I generally put the new sensors in and load up the valley holes with red RTV sealer. Then I put the rubber cap in the hole and seal it off. Water entry is guaranteed to be history.

Some dealerships use permanent silicone in the big tubes and just goop the whole shebang and discard the rubber caps.