repair update

[Louie cat]

Anyway here is a sad situation for me today, the service manager calls me up at 7 this morning to tell me they went through the car and found it was running 10% too rich so they corrected that,and that indeed the knock sensors were bad. He also told me they weren't affecting the performance that I should be okay since he and the tech went for a test ride.
So I go there and return the rental and get my car back thinking it will be back to its fast self again, as soon as I drive away it felt like a slug no power what so ever,how can they say that is acceptable??!! I got home and called back and explained what was going on, he basically called me crazy that I need to come back and go for a ride with the tech. What efn good will that do it wont change the fact it is slow AF! So I brought it to a different dealer down town FT lauderdale, and they seem to very much believe my story and said not to worry they will make sure the vehicle is like it was as new since they have real specialists there.
I am no dummy when it comes to cars I probably know more that those clowns at the other dealership. IMO I think the car has what is called engine protection mgmt. In other words the knock sensors go bad so the computer automatically retards the timing to prevent detonation which can damage a motor and the valves thus leaving it excessively slow for its own good. Does that make any sense?