Thanks for the info Jim. I had black smoke coming out the exhaust when the engine lost power. The black smoke could be the ignition cutting out or a super rich condition. I would not think that the intermittent CTS would cause what I was experiencing, but thinking of your failure experience I am not so sure now. However, I was getting the intermittent check engine light all day without runability issues, so... Hmmm.

I recorded the CTS plug positions at the ECU so I can run a continuity test while wiggling the wires today after work. I have a new plug I could wire in if the wires at the plug are faulty. If the wires seem good a new CTS is cheap.

Quote Originally Posted by JimCT_9C1 View Post
Sharing my experience with bad coolant temp sensor (CTS) on my 95 LT1 -
My CTS failed low (constant, not intermittent), but not failed to the point that a code was set.
Flooded out the engine - wouldn't run when warm. Could start it with flood clearing mode (throttle to floor, no fuel) but would flood out after running a few seconds. Pulled the CTS connector to cause a hard failure. Started and ran well enough with code set and no CTS to get me home.

Testing without the sensor in play (and thus wiring as well) may help narrow things down.
Note my experience was with LT1, so others can chime in on any differences to your application.

Hope this helps -
Jim