y-pipe question....need help~~

i just had my Budget y-pipe installed couple days ago. and next day when i driving it BATTERY and BRAKE LIGHT came on. and i was just reading through some instruction on installing it and saw this.......

SPECIAL NOTE: If you have extra $$ lying around, why not change out your old o2 sensors? REMEMBER, after you're done installing the ypipe. Besure to remove one terminal to the battery to RESET your ecu.. :)

you guys think this is the reason why those light came on???? i don't know what to do. i need you guys to help me out....:confused: what can be done? and how is it suppose to sound like?? right now it sounds like 80 camaro at low rpm and it gets lil quiter at higher rpm. i have budget y-pipe and apexi dunk muffler with resonator taken out. THANKS~

Did you put it in yourself? Make sure the negative and positive battery terminal's are tightned down, and look for any loose wires, if you can't find anything, take it back to the place that installed it, and tell them they messed up your car! :( BTW, I wouldn't drive with the brake light on, you may have a problem with the car, unless you have ABS, then you may just have a problem with your charging system or loose terminal...