i was wondering can a gsr highflow cat fit a 99 integra LS?..also is it safe to run a OBD2 car without one of the 02 sensors (the one that goes on the cat.)?..thanks

yes and no. the cat will fit. but you need that other o2. lots of people thnk cause they have that one closer to the exhaust manifold they dont need the one near the back. you want notice to much of a difference in performance with only one. but you want be running right. But i have heard of people deleting the second one.

it'll throw a check engine light for the second cat.

just have a bung welded onto the cat and you should be good.