I am going to remove my cats, can i have a shop weld up pipe or do I have to buy a x pipe without cats? will a mustang one work? or is it a custom job?, I want i already had a shop cut off the 3rd cat and weld a straight pipe in there,but i am going to put an x there , and weld pipe where the cats used to be , while at it i am replacing the o2 sensors, i need some expert advice, i don't have a lot of $$$$ so if i do not need to buy a kit i'd like that...also how hard is it to install the headers on our cars, saw some for our cars i'd like , help me out. :feed :Beer :give