Question

in which of these cases is the catalytic converter most likely to be saved?
a. when the catalyst is severely overheated
b. when contaminated by lead and silicone
c. when contaminated by carbon
d. when the converter is physically damaged

Explanation:

Carbon contamination in a catalytic converter can often be addressed through methods like a proper engine tune - up, driving the vehicle at higher speeds (to burn off excess carbon), or professional cleaning. Severe overheating can cause permanent damage to the catalyst structure. Contamination by lead (which poisons the catalyst) and silicone (which can coat the catalyst and block reactions) usually leads to irreversible damage. Physical damage (such as a cracked substrate) also typically cannot be easily repaired.

Answer:

C. When contaminated by carbon