need help quick!!!

ok, my check engine light came on yesterday so i had a diagnostic done on my car and these were the results: P0133 Rear Air/Fuel Ratio (A/F) Sensor (Bank 1, Sensor 1) Circuit Slow Response AND P0141 Secondary Heated Oxygen Sensor (Secondary HO2S) (Sensor 2) Heater Circuit Malfunction. Also, I recently put on some headers a high flow cat and a brand new 02 censor about a month ago and now i think i have an exhaust leak but i don't know how to be exactly sure. I have to take emissions in a week and i have no idea how to fix these problems. please help!!!!!

down in florida, any 'shaky' car would pass an emissions test with nearly empty tank of gas and 4 bottles of rubbing alcohol... don't know how much tests have changed, but it's a thought.