EJ8 GSR-T

Allright so i got a straight pipe for my 98 civic ex, and i also got this inline o2 sim, so that it wont throw the CEL. I installed it and it works for like maybe a day, then the CEL comes on....also the o2 sim i got only works if you still have the original sensor, but my test pipe dosnt have a hole for it....so i zip tied it to my shift linkage...but it rattles and i know thats not a good place for it, So if anyone has any tips or anything they would be much appreciated...