Car was completely stock first mod was a Invidia catback right after install load bank 2 o2 sensor cel popped I changed it with a Bosch o2 and it just keep popping. I later troubleshot that if I put in the dB killer it would stay off longer but once I hit VTEC or a higher rpm it would pop it again and with it out even driving under 3k rpm it would pop it sooner. Any suggestions this thing driving me crazy.

 

post a link of the cat you have. you may not have a real cat, in which case the 2nd (downstream) O2 sensor will read incorrectly (cel) and try to indicate that the cat is bad. you may be able just ignore it, or bypass it.

 

It was a catback. I did not switch the cat out. If my oem cat is old enough or it is bad will it pop o2's ???