01 V70 Sulfur Smell and Roughness

[zero324]

I have recently started having an issue with engine roughness when driving on the highway at speeds of 55-65 when I go to accelerate at those speeds I notice a lack of power and roughness and also during that time I also get that rotten sulfur smell. I have suspected for a while that a coil pack may be going bad but due to no CEL i'm not sure which one because at idle it seems fine. If I am at low speed and accelerate hard it has no problems with power. One other thing I have noticed is that when coming to a stop the rpm's will go down to 500 and feel rough but go back to normal but it only does that during a sudden stop which around here is alot due to construction. I have just within the past 2 weeks been getting a CEL of P0442: Evaporative Emission Control System Leak Detected (small leak) which from what i've read points to the J hose which I do plan to do soon but from what i've read should not affect driveability of the car which i'm not sure is true or not.

I recently had to replace my catalytic converter again due to the aftermarket one being poorly manufactured and would blow exhaust gaskets. This time I got an OEM one and put new 02 sensors in.

Any ideas or suggestions ?