I am getting erratic idle sometimes and its showing around 600 or so on my scanmaster which I think is low for an a4. I have no codes showing at all.
I have newer 30 svo injectors and tuning with my maft but the car seemed to have this erratic idle occasionally before the injector swap. I tested fuel pressure and fuel reg and they both seem fine. I have not personally changed out plugs or wires and the car has 60,000 miles on it. I did lose a water pump last year and maybe its my opti but car other than the idle is running good and numbers on scanmaster look good.
I would think if opti was acting up would be getting misfires or something. So far the car is mostly annoying and hasn't stalled yet. So it sort of sound like a lopey cam for a minute or so at lights and then seems to go back to normal but again around 600rpm.

Air filter is new,fuel filter is new.Tps is new. Just wondering what else to do or check. Other recent mod was asp underdrive balancer but got overdrive alt pulley and it holds 13.3 or so at idle. I also replaced alternator with brand new gm a week or so ago and have newer optima red top.