i have an obd scanner the code Po135 comes up an replaced the o2 sensor before the cat and tried to clear the computer. the check engine light goes off for a few seconds then comes back on. i bought the o2 sensor from autozone. does anybody have any suggestions?

 

Shop manual has two pages of tests/checks for this code.
Have you replaced this with a premade sensor with a proper plug on it, or a make fit universal sensor wher you have to reuse part of your old o2 sensor harness? Check continuity and ground as per shop manual pages 11-69 nd 11-70. If you have a good sensor, check for wire problems between the o2 sensor and the ecm.

 

Hey did you ever find out the problem? I have a 2005 civic and am having the same problem!!