Sulfur smell in cabin of 1998 Toyota Camry

I’ve had a sulfur smell (exhaust) inside my car since I got rear-ended a few years back. I had the trunk checked for leaks in case the exhaust was getting sucked in that way, but all was tight. I hate to replace the catalytic converter, only to find that doesn’t fix the problem. I did have a new oxygen sensor put in, but that didn’t work. My check engine has been lit forever, but went off for a while when they replaced the oxygen sensor.

Your converter is bad. Replace it.