Will the ECM run the car rich or anything if I leave the fan on all the time? I leave it off until it heats up to 160 (I have a 160 stat)and then I turn it on and it doesnt really change unless I am running it hard in the afternoon. If i drive normal in the day or night, or race at nite, it doesnt really climb any higher than 160. Could this cause the car to think it is still heating up to normal operating temp and run it rich? Will it cause any other problems?

Thanks a lot in advance!

 

I think it would run rich. I had a CTS go bad and it told the ECM that it was cold and it ran rich. Another effect of that is the fan will not turn on when the car gets hot as the ECM thinks it is cold. The temp on the gauge has nothing to do with ECM as the gauge is controlled from the sensor on the left head and the CTS is located just under the TB on the front side of the intake manifold. You indicated you were operating the fan manually and there might be a connection with the fan not working.
Bob