Any advice on removing CATALYTIC CONVERTER and installing two straight pipes !!!

[Slow325i]

Well looks like my stock CATALYTIC CONVERTER is clog up , sometime on high RPMs i can see brown smoke coming out muffler and it smell on eggs ,so 100% cat is bad

I was wandering did anyone try pull CATALYTIC CONVERTER off and install two straight pipes
Example: when i pull 4 stock Catalytic Convertors from my 94 Mustang GT and install Off road pipe i gained some power and it was easyer spinn tires by changing gears

I was wandering will stock ECU have some kinda shock or meybe Check engine light will come on or anything ???
BTW i won't have any problems with emission because this car is driven less tham 5000 miles and it will be Exempt

And does anyone have any sound/video clips without CATALYTIC CONVERTER ???