Catalytic Convertor/ Plugs

[Royal-T-Ltd]

What is the operating temperature for the catalyst to work? TIA
- Also do you guys switch to hotter plugs for emmissions tests?

 

[gofstbuick]

Catalytic converters begin to work once the shell temp exceeds 300 degrees. You'll know it is fully functional once outlet end shell temp is at least 100 degrees hotter that inlet end shell temp. Also, because the back half of the cat is responsible for oxidation (HC and CO to CO2 and H2O), O2 content will drop near 0.3% to zero and CO2 content will rise to the 13.8% to 15.0% range.
Regarding plugs, the colder plug takes less energy to fire, so I would stick with the colder plug.