To start off i have a 89 740 gl with 133,654 miles. I had to replace my oxygen censor and cat converter about 2 weeks ago. That had started the smells in the cab very strong egg smells and out side if the car to, also strong exhust smells to. this was before and now after the parts were replaced. I was wondering whats wrong now and if it was done proprally. Now with the Trans whineing. It happens at all different times and sometimes it wont do it for like 5 days and sometimes it is very low sounding but others it is ear piercing loud. It usually never happens below 25 mph and as i go faster the noise is lesser and lesser until i hit like 70 mph. One last thing there is a weird huming noise comeing from the front of the car but i can only really hear it when i am in the car. Any help can be greatly appreciated. Thank You