I was told that i can remove a o2 densor and just get the car tuned so they can tell it or what ever that its not there so there are no problems. Or should i get the bung welded in so i can just keep the o2 censor and maybe not have another problem on my hands ?

 

the front o2 sensor location is too close. the cat o2 is after cat. the best location is down towards the end of the downpipe.
you can replace the stock rear o2 sensor with a specially adjusted (software) wideband, but why bother?
if you can remove the cat you can use the test/race pipe's bung.

 

Good point if i got with the car delete. Ill have to order one then i guess.