2001 Integra LS, B18B1 engine type.
Service manual says the primary oxygen sensor is located in the B exhaust pipe, not the TWC. Acura parts guy says both 02 sensors are on the TWC.
Which is it?
Here's why I ask:
Midas replaced the B exhaust pipe. The MIL came on 2 blocks out of the shop, and they said the code "indicated a problem with the H02S". Geniuses reset the ECM, didn't troubleshoot the problem. The MIL came on again after driving about 5 miles. Of course Midas categorically denies they could have broken the H02S. "It's nowhere near the B pipe."
NEVER go to Midas.
-Al