My car is a 2002 Z28 A4. I installed headers on it about a week ago. I have the rear O2's turned off. My car is throwing a low O2 sensor reading code. Why is it doing this and how can I stop it? Can anyone please explain? Thanks guys. The car has full bolt ons now and it idles at around 500 rpm. But this time the code came on on the interstate. It doesn't drive any different and it still pulls hard. I did have the O2s spliced but I bought the extensions fearing that the splice might be adding some resistance. I haven't been able to get it reset again but could this be causing the problem? Thanks again.

 

Yes it could. throw the 02 extentions on and get it reset.

 

possibly near melted together sometimes grounding it out causing it to not cycle..

 

i would check the splice, extensions are worth every dollar

 

my thoughts exactly.