O2 sensor with headers

Hi again. I am intending to fit headers to the Astra, ( Z22SE) and was wondering if others have done this. Using most of the original zorst, but removing the center resonator.

Has it affected the O2 sensor downstream from the Cat? If so, what remedies have people used to extinguish the MIL if it comes on?

If you want to do a full cat delete (removing both cats) you need to fit a lambda spacer on the second/post cat sensor to move it out of the gas flow. 50mm is enough.
If you are just wanting to remove the small pre cat and center silencer it will not need any other work to prevent the eml from coming on.
I have 4-1 tubular manifold, no pre cat, 2.5" manifold back exhaust, 200cpi sport cat and both silencers. Its still very loud. Did try a center box delete but it was far to loud, could be heard 5 miles away driving steady under 3000rpm :eek::eek:
With the headers that I have, the pre-cat will be going, but I hope to retain the/a full cat. I also hope to have a smaller center resonator, as I don't want to attract too much attention!! :sneaky:

Thanks for the reply and info !! :) most appreciated...............