down on power

I got a 2004 pre-runner 3.4l and last month I discovered that the first catalytic converter broke in half jamming the second cat and both were ruined So I punched both cats out.(being cat-less is interesting to say the least)

Since then my truck has not been running the same all round. I do not have a lot of power down low and the power doesn't kick in until close to redline. And it is idling kind of rough almost like it doesnt have enough fuel. Im hoping that the O2 sim from URD could fix it but I dont know.

thoughts or suggestions I cant live without my TORQUE!

i also got another question, Does anyones first gen backfire? (or blowback whatever the correct term is) because mine does very loudly now the cats are gone, it sounds like a gun shot and the other day my buddy was behind me and he said when i backfires a 2ft flame came out so this can also mean i am running rich. But seriously does anyones truck also do this??

btw i got a magnaflow muffler