How much should the temperature increase above the catalytic converter inlet temperature reading be?

The correct increase in temperature above the catalytic converter inlet temperature reading is significant for evaluating the performance of a catalytic converter. An increase of 38ºC (100ºF) indicates that the catalytic converter is functioning effectively. This temperature rise is a measure of the catalyst's efficiency in converting pollutants from the exhaust gas into less harmful emissions.

When the exhaust gases flow through the catalytic converter, they undergo a chemical reaction that not only reduces toxic emissions like hydrocarbons, carbon monoxide, and nitrogen oxides but also generates heat in the process. A temperature rise of this magnitude confirms that the catalytic converter is actively doing its job, as a substantial increase implies that the chemical reactions are taking place, effectively converting harmful byproducts into safer emissions.

If the temperature rise were significantly lower than this, it might suggest that the catalytic converter is not functioning properly due to issues such as contamination, damage, or inefficiency in the catalyst material. Thus, knowing that a 38ºC increase is the expected standard helps technicians diagnose potential problems with the exhaust system and ensures compliance with emissions regulations.