well sortya i have a hiflow cat to replce it and well i finally took time after work today to jack up my car and grind off the horribly rusty bolts on the rear of the cat. the front ones i can trun nicely.
i wasnt gona fight them .
so after about 2-3 hours of grinding in the fricking cold it came loose. but then oh wait i didnt want it totally loose yet becuase it was damn near dark out by then. so i have a really nice sounding car until i can work on it again. and there is spose to be a winterstorm coming in for tomarrow tih like a ft of snow and bitter cold temps.
so here is my question.. in the mean time my hi flow cat is just sitting in here. it doesnt have a hole for my 2nd o2 sensor so what im asking is what size hole is needed for the 2nd o2 sensor. it loks like you would need about a half inch. does this have to be threaded or do you just make it fit. buy a gasket. i need to know. i would rather use my sensor then unplug or bypass the system