I recently just had a bunch of work done on my Durango such as rack and pinion, ball joints, tie rods, lower control arms, and fixed an exhaust leak. It has almost 115k miles on it and notice I smell sulfur at about 65-70mph along with losing gas mileage and sluggish performance. Any ideas on what it could be? I was thinking catalytic converter, was going to take it to a local shop but they are booked up and I refuse to deal with my sketchy local dealership who dose piss poor work at best. I don’t have any check engine lights or any codes either so I’m at a loss.