jus replaced knock sensor

What is your question?

ok. so i took my truck to mechanic. they put on computer and it said the knock sensor was bad. truck was running sluggish like it had bad fuel and maybe the fuel filter needed changing. wasnt prepared to spend what i did. but my question is, got the new sensor put in and well, it still runs sluggish the computer also said my TCM was either low or bad, cant remember what he said. whats wrong with my truck?