weird issues with my 01 taco...

hey guys,
wondering if anyone can help me here. so here goes....

back in the summer, some ghetto thieves tried to hack off my cat converters, thank God they werent able to, as i'm assuming people came by and they took off as the front of the first cat was completely cut off but back of the second cat was just started. so with that, i had it welded, but the shop i took it to said they couldnt completely weld the whole thing, well, they could but it would have cost a lot more, as they would have had to take off the cat and then weld, which would have cost $200+ rather than just $50. wasnt a big deal, as it did leak alittle, and the cel wasnt coming on anymore. BUT....

every since then, when im at a complete stop, in drive, and then ready to take off, as im easing off the brakes and the truck starts to go, it feels like the truck is going to die and it actually did once. so i would have to ease off the brakes with my left feet and acelerate with my right feet to prevent it from dying. never happened before, so i assumed it was just bc of the leak by the o2 sensor. so a few weeks later, i took it to my bro, since hes a welder, and he weld it completely for me. it seemed better at first but it will do that every so often only. now that its cold, it hasnt done that anymore....BUT now....

now my "brake" lights will come on...is this normal also? my brakes works just fine, pads are fine too...i notice it only comes on in the morning when the truck hasnt been totally warmed up yet.

CAN ANYONE HELP ME? thanks TW....

 

ok, will check for that tomorrow. thanks...