I just installed a set of Flowtech LT header on my '01 Z28. I turned off all the codes for the rear O2's with LS1 edit. I have about 200 miles since the install and now I am getting an SES light. The codes are Bank 1 and 2 Sensor 1 low switching. I hooked up EFI live and looked at the O2's waveform. At idle it's very choppy and eratic. Once the RPM are up to about 1500 or so, they start switching the way they should. Is this normal are should the still switch at idle? I think I am too rich at idle, could this cause the problem. Thanks,

 

It has been suggested that "burning in" new headers will foul O2 sensors. You might need some new O2s.

 

That's what I was afraid of. I'll leave it a little longer to make sure they are completely cured and done. Don't really want to fry another set of o2's if that's the problem.