Originally Posted by pecos
I don't think I have any of those. Stock muffler.
You should have a pink coding plug 30-87-87a in the spot that says remove this plug, on this diagram I grabbed. It's okay not to have a plug but it can be very different running.
If you have no plug there, your 1100GS doesn't use your O2 sensor, and it idles much richer, although usually not so rich it won't run.