Idle issue

[Gitbox]

I recently had my throttle bodies off and cleaned the gunk from the butterflies. After assembling, I did the unauthorized TBS and found that closing the idle air screws did not lower the idle enough to have to bump up the idle stop screw. Odd, I thought. The sync went fine, but on the test ride I felt a very slight surging at normal highway speed like someone was pressing on the rear brake slightly and intermittently. Never felt that before. Power and acceleration are fine. It almost seems like an intake air leak but everything is nice and tight. Vacuum lines are all good too. No codes or problems in DIAG mode either.

Any ideas?

 

[bluesdog]

If you have not already done so, confirm there are no air leaks by spraying some starter fluid at various spots at the intake while the engine is running.