i had a crack in my exhaust manifold recently that i repaired and i had been smelling smells and experiencing exhaust sounds due to it, i procrastinated on the repair until one day i was going up a hill on my way home and all the sudden i couldnt get over 50 miles an hour until i was flat then only up to 75 maximum, i finally got the crack repaired and figured it was causing my o2 sensors and junk to cause the acceleration problem. well after i got it fixed i have a little bit better acceleration but still a little bit of exhaust sound and the engine is still shaking pretty good. any ideas? i believe its my cat converter but i cant be sure