Considering knock will destroy your pistons, rods and block... and having no motor can really slow your truck down... knock can really slow down a truck.
the more your truck knocks, the more the ecu pulls timing... when you start seeing like 8-10 degrees of spark retard, your truck will feel like a turd.
There's lots of discussion in the archives about knock and it's causes. Please do some work and not waste space unless you are completely stumped. Thanks.