Help!!!!!!

[pacman69]

my 2005 ex cab 4.8 v8 is driving me nuts,she has 219,000 miles,no oil use...but seems like every year when it gets hot it runs slugish an usualy starts settitng off knock senser code,but now no codes an as long as you dont give moore than 1/4 throttle she runs ok....but if you need to get out in trafic an gass her its bogg city till you start backing off the gas,wouldnt even spinn in the gravel! no codes an no one seems to know whats going on!!!! even a gm dealership is stumped! usaly when this happins it stops after a lil driving....but so far been a week an still the same.really dont wanna trade it an have a payment again,but im at wits end.......replace both knock sensore last summer an the under intake wiring harness for them.