I recently failed an emissions test because my CAT and EVAP readiness monitors were "Not Ready" following a reset check engine light a few weeks back, which told me that the engine coolant wasn't running hot enough. I've confirmed this with a ODB-II scan tool.
According to pg 13 of this document (which is for a 2002, but I assume they are similar), my engine coolant temperature needs to be 176 degrees F for the CAT monitor to start running. My scanner is telling me that my ECT is running at ~160 degrees F.
I can't figure out if this means a sensor is busted, or something else (like cold weather) is causing the ECT to be that low. Can anyone recommend a next step that I might try on my own instead of taking it into the shop?