O2 Sensor?

[Edibrac]

So did you try any of the suggestions given in this very thread?

[steve99]

Originally Posted by mattyd97

So I just got off the phone with someone at K&N. They told me if I've had the CAI for almost two years it's most likely not the intake unless I didn't take care of it. I've only put about 8k miles on that intake at most, so I really don't think that would be an issue; however he said since my secondary cat is bypassed I have to turn the sensor off for that cat. Does this seem right to you guys? Just looking for a couple of opinions. Thanks.

Bold bit is incorrect,

1. only primary CAT in header is monitored by ECU. Secondary cat is not monitored.
2. The cel code produced when you remove the PRIMARY CAT in header is P0420, not a lean code PP219A "Bank 1 Air/Fuel Ratio Imbalance.
3. Removing even both cats will NOT cause the lean code just the code P0420 cat efficiency. assuming the 02 sensors was not damaged and installed correctly no exhaust leaks.
4. Even straight piping the entire exhaust wont cause car to run lean.

you have a perceived lean condition could be many things. see my previous posts and like another guy said you need to monitor LTFT , commanded AFR and Actual AFR.