2007 RXT P0326

[Cowlitz77]

2007 RXT P0326 code---engine hesitates at about 5800 rpm's--throws the code, but will pick back up and run up too 7800 rpm,s---have drained fuel tank and replaced gas with premium fuel--changed plugs, check knock sensor ohms--4.8 ohms--not sure where to go next--any help?---thanks