The O2 sensor is in place, only the CAT is gone. SES bulb is fine, it also turned on not long ago when I left the fuel cap opened. i'll double check later. If it's not throwing a code because the CAT is gone I'm fine with it. that light being on all the time bothers me a lot lol. I was just wondering why it didn't threw a code. My next mod will be a PCM anyway. Thanks for the replies.