1995 Buick Roadmaster Q&A

1995 Buick Roadmaster Question: backfiring throw carb

i bought a 1995 buick roadmaster for a hundred dollers.The guy i bought it from replaced the moter and now backfires thro the carb when the moter is cold and the check engine light is on the code comes up as a o2 sencor not to worried about that. If you sit with it in drive the check engine light goes off untill you give it gas. can anyone help me ive giving up on the thing thank you and god bless -
Answer 1
FIRST THERE IS NO "CARB". YOU MEAN INTAKE. WHAT ARE THE CODE NUMBERS. -