My 1999 V70 XC has 90k for miles. Today I had to accelerate quickly from 25 mph. When I did so, there was a loud pop from under the hood and the engine lost power. I had to pump the accelerator to keep it running. At a steady 2000 rpms it seemed fine so I limped home. When I started it again and let it idle it was very erratic. It also lunges and acts like it is starving for air (or fuel?) in simple neighborhood or city driving.

A couple of odd sounds and smell accompanied this problem. Aside from the popping sound when it initially happened today, it emits a very throaty (4 barrel like) sound when I try to accelerate. There was also a sulfur smell in the passenger cabin, but not the engine compartment. Any ideas guys?