where can i get a O2 sim for a 2001 4.3 blazer?

my friend has 230,xxx + on his blazer and his cat is clogged he is going to take it out and put a straight pipe on but he has a o2 sensor behind the cat and he doesnt want to throw codes. so where can i find a o2 sim for a blazer?

ask on some blazer forums

crap that is like driving 50,000 miles a year or 1000 miles a week..jeez

yeah he drives ALOT. they all freeway miles but he maintains the car vary well engine wise. the body is a different story. he uses syn and changes every 6,000.
but he drives for a living so the miles add up but he makes DANG good money but he is very cheap.