Po172 is bank 1 one sensor 1, system rich. In your first post, you said intermittent rough idle. When you open the throttle, it should bypass the iac. I'd use and check fuel pressure, for a start. Not only check for correct pressure, check that the pressure doesn't drop like a rock, with everything off. You might force the system lean, if possible, to see if 02 sensor will react.
Monday, November 21st, 2011 AT 5:34 PM