my nissan quest sputters off and on

i have a nissan quest 1996 model. the check engine light came on and ihad it hooked up to the computer. there were three differentcodes pull up.my nissan was bumping into gears and i was smelling gas real strong. the codes were computer,tps sensor and knock sensor . so i replaced the computer did not solve problemthen i replaced tpsand it stated shifting alot smoother but now when i accelerate it sputters and then goes and sputters and then ect. i am thinking it is the knock sensor maybe or maybe not what do ya think?

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