Need help please

I just purchased a 1980 Fiat Spyder 2000. It is the later year fuel injected model. The trip home was about 60 miles. Everything was fine for the first 20 miles. Then, if I had to stop for a traffic light, the car started to hesitate when trying to move forward. It is a manual gearbox, and the car would lose power and buck. It got steadily worse, so I pulled into a parking lot and thought letting it cool down might help. The temperature gauge was reading around 190F, far below the red area. After about ten minutes, I started off again and it drove perfectly. The same thing happened about 20 miles later. Same thing, I let it cool down. After getting home, it was getting darker and my wife took the car out to drive it around the block. She noticed that there was a light illuminated that said "Exhaust temp". Has anyone experienced this problem? Could this be a faulty sensor in the exhaust manifold? Thanks for any wisdom!

sure, the sensor could be bad.

why do you expect the sensor to be faulty? could be that the sensor is just fine and it is trying to tell you that the temp in the exhaust is too high.

which could be caused by a plugged catalytic converter, or too rich fuel mixture.

Correction, the light that was on was the Exhaust Gas sensor. Of course, the sensor could be doing it's job Mbouse, but I know from experience in other systems that sensors do go bad. The point of my post was to see if other Spyder owners had encountered the same issue, or in case it was a common problem.

Hi.
I dont claim to know much about your vehicle, I do know that on mid 1980-1990's Fiat other than the light showing there was a simular fault which was caused by the distributor, when the vehicle got warm the wires on the inner distributor module seperated and once cooled down they went back together again and the car drove fine until it warmed up again.
Maybe it could be a simular sort of fault.
Just a thought...if it helps