After replacing bad catalytic converter car's exhaust is extremely loud

Hi my car had a really bad catalytic converter and drove it like it was for almost a year until I had enough of the noise and smell. So just recently had to order the part and some other parts as well to get it fixed. Well after it was put in a few days later my car started up again with the loudness. Tried jb weld did okay for a day or so and now I don't know what to do. Will removing the converter help or will it just get worse? Please help!