156 won’t start

[JohnnyNat]

Hi, I have a 156 ts that will not start. I was travelling along a freeway when my exhaust suddenly got a lot louder. I pulled into a service station and before I switched the motor off, it sounded like I'd lost a muffler. I turned the motor and tried to locate the issue. When I tried to start the engine, it turned over but would not start. Later after doing some research, I removed the exhaust system excluding the last muffler at rear of car. Upon inspection, I could see right through the catalytic converter as there was nothing inside it. Is that normal?
I replaced the exhaust system and still no joy. Any idea as that was the extent of my mechanical knowledge

[Citroënbender]

When you crank the car, does the tachometer needle move?