BRICH60

I have a `98 integra with 99k miles. Based on the trouble code, per my parts store, i replaced the rear oxygen sensor this past weekend. My check engine light did not go off. I took it back to the parts store who read a new code of bad catalyitic converter.

Does a cat go bad? Why would it show a bad oxygen sensor at one time, then when replaced show a bad cat the next time?

Lynxs1981

The cats can go bad, but it's more related to deposits lessening their effectiveness. As to the O2 sensor, the guy probably mis-interpreted the code.

pslsnakes

Catylic converters usually have a life of about 100,000 miles. Some times a more, some times less.

Do you have emissions in your state? If not, I'd say go to an exhaust shop and have them weld/put in any old cat.

cruzalekz

this is a problem with the scanner, parts store scanner is probably a cheap one.
expensive scanners would say "rear o2 sensor below threshold"
if you get that code, this is where a tech comes in and does a o2 sensor swing test with a scanner, You have two o2 sensors, one on the pre cat side and one is the post cat. Normally, pre cat o2 sends a faster signal than the post cat.
In your case, your pre cat and post cat o2 sensors were swinging the same rate and because im a technician, i interpret this as a bad/degraded catalytic converter and not a bad rear o2 sensor.
time to get a new cat..

by any chance is there another code besides the rear o2? sample a misfire code perhaps or a lean code

just trying to figure out if your cat went bad as a result of another engine problem.
good luck