Your bike's going to be running richer than before in the closed loop, or rather it's not going to be running so lean - but that's all good, it's what is meant to happen.

I'd have a guess that your tick-over/idle speed was set prior to fitting the O2 controller and its then state of weak tune. Have you checked or adjusted it since fitting it?

Probably worth making sure the idle speed is well up into the 1400-1500 bracket as an easy thing to do first...

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