On my 2001 tbi motor there is a 1 wire temp switch for hi temp right near another 1 wire thermistor sensor for the guage. As you said, the one towards the front of the motor connects to the MEFI and sets a CEL for hi temp. The replacement has 181 stamped on it. Possibly on at 200 degrees and off at 181?
The other as you said feeds the gauge.
Didn't see the 2 wire sensor but probably down on the side of the block where it can't be easily seen. Here's a picture of the 2 single wire ones with the orange wire boots:
Last edited by Rossterman; 09-02-2013 at 04:50 PM.