So I recently installed an Asura 3" HFC on a MY07 and now code 0139 (secondary o2 slow response) pops up every 5-10 miles after I reset it. I've tried the steel wool trick and antifoulers and nothing seems to have any effect at all. Is it possible the secondary o2 sensor is toast? I inspected it again today and it looked fine but maybe I damaged it upon installation of the HFC. Any thoughts?

 

buy a new O2... whats it going to hurt?

 

re-install your cat and see if the code goes away

 

A new secondary o2 sensor is roughly $200 so I would like to make sure it's the culprit before I buy one. My oem cat triggered the 0420 code (catalyst below system threshold) so it might not be the best diagnostic tool. I'm just wondering what other MY06+ owners have experienced after installing a HFC and what they did to eradicate any codes. It seems odd that the code occurs so frequently and quickly on my car, which is why I want to know if anyone has experienced this.