Bernone

Need a little advice if possible. I have a 98 Civic EX that has about 120K on it, tranny was just replaced with a used one. Within 2 weeks of getting the car back the check engine light came on. Took to the same mechanic that replaced, they said the light is reporting a bad torque converter sensor, but that the converter is working fine, is just the sensor. Said they would get a new sensor to replace but needed 2 weeks. When I called to check back in, was told they needed another week. Check engine light goes on and off intermittently and has now been off for several days. Called back to the mechanic and was told that they can't do anything while the light is off. Seems to me like they are waiting to see if the sensor will just burn out so the check engine light won't come on anymore and they don't have to do any additional work. Any thoughts or suggestions on this? Is it possible for the sensor to be bad but the part to be fine? The only issues I am noticing with the car now is a bit of hesitation when I am accelerating and is somewhat clunky shifting when I am idling/going slowly in traffic on the freeway. Any advice would be appreciated.