just got my pipes with cat and dpf delete. going to install but noticed that i do not have any brass fittings in any of my mounting holes. i just have 4 welded nuts on the pipes. is this correct, are the threads the same as oem. is it even possible to remove the sensors without damage? put a small box end on one felt like it was going to break off before coming out. i am afraid to start this project with so many unknowns. i am in garage not knowing what to do. i so many threads about missing fittings and wrong threads, has this been corrected?