Originally Posted by
Delco
If it reads properly when cruising then it is not a O2 or wiring issue.
The O2 in this case will just tell you whats going on, what type of forced induction do you have , it couldbe biasing the air to one bank making mixtures side to side uneven , hence your issue , you also may have a air leak on that bank as well.
It may be you just have a idle tune issue , putting a stock cal will be no go on a blown combo as the dynamics are all wrong , change your fueling/spark at idle and see what happens , poor spark burn will also cuase the issues you describe