[V]

if it went on and off then there is a code in the ecm. Most of the time, codes will remain in the history of the ecm for about 50 starts(so that you can get it checked out without clearing the ecm upon the next startup) I suggest pulling the code now and see where that leads you.

If it is 45 again, keep in mind code 45 does not always mean just a bad o2 sensor(usually code 13), oh and yes, the tpi cars only have that 1 o2 sensor.

Code 45- When the ecm has detected a rich exhaust condition, and the O2 sensor voltage remains at more the 0.7V for more than a minute, with the throttle angle between 3 and 40%. Look for leaking injectors, excessively high fuel pressure, leaking egr valve, bad tps and vapor control purge valve.