I restarted the 300te late one afternoon and it decided to turn over a few hard times then sputter out. A sulphuric smell arose? Hmm. Dead Catalatic converter? Initially we had the Fuel System as culprit, yet now the ignition system may be the issue. Any feedback will be feedforwarded.

Is the battery overcharging?

Sulfuric acid can be released from the battery. Start there.

The battery may be the smell, yet the car is not starting, just turning over and over no ignition happening. I replaced fuel filter and checked fuel, its ok. Where is a good place to check for sparking or trace a electronic problem?