2G P0505 IAC / ISC?

[Spades]

Car idles perfect, but getting the P0505 code. Have replaced the isc, cleared the code and still comes back after about a week of driving. No idle surges, no problems what so ever, but the code keeps coming back... Any tips or suggestions on what else to check?

 

[Zorak]

I would try doing a boost leak test. My girlfriends gst threw a p0505 after we unknowingly created a boost leak, but it still ran and idled perfect. Found the leak, sealed it up, and haven't had the code come back since. Make sure you check everything from the intercooler/piping up to the throttle body, including vacuum lines at the manifold, injector seats, and the pcv valve/pcv line from the manifold to the valve cover. Hope this helps