99 grand am coolant question

i have a misfire, says something about temperature closed loop, well i was reading about O2 sensors and their involvement with the closed and open loop process when i came across the coolant sensor, well i cant find anything on coolant sensors, and was wondering if the 99 grand am even has a coolant sensor and if its possible to get one...or if the coolant sensor would actially be the thermostat, which i already replaced???????????

I don't know anything about the closed loop deal you are talking about, or which motor you have but the 3.4 L had a coolant sensor.

It is on the driver's side of the engine, to the front of the engine between the water neck and the block, under the throttle body. Fairly easy to get to and easy to change. $7.00 at Advanced Auto.

This Temp sensor was also the cause of my GA not starting and "EGR error codes".