05 Colorado, z71 LS 3.5 i5, 305,000 mi
I have an 05 with 306k miles on it, but just recently started having an issue when idling. It doesn’t seem to be a misfire, because it come and goes so randomly. Replaced fuel pump and filter, and camshaft solenoid. Could be an o2 sensor but is there anything else I am overlooking?