why does my car have no power and it vibrates. on 2000 Saturn LS1

Just replace injectors. Runs the same. No water in fuel. Changed fuel filter. The Backing the car out of the garage the peddal is on the floor to get it to move very fast. Driving it back into the garage, the power assist brakes don't seem to work.I'm thinking, ign. module or maybe catalyic convertor. Car feels like the whole thing is being choked to death.

Asked by for the 2000 Saturn LS1
cat converter. it literally cannot breathe.

That is what I had concluded. I checked the spark on each injector and all good, cleaned plugs and all looked clean and good there too. I guess the best place to get a new cat converter installed is at a muffler shop.

Thank you for your confirmation. I really appreciate it.