Final answer:
RTV sealants are typically used as gasketing materials rather than to secure threaded fasteners. Anaerobic sealants, however, are used for thread locking but their fumes can be harmful to an O2 sensor. The correct option is both A and B.
Step-by-step explanation:
The question concerns whether Room Temperature Vulcanizing (RTV) sealant is used to secure threaded fasteners and if fumes from an anaerobic sealant can damage an O2 sensor. First, RTV sealants are generally used as a form of gasketing material, rather than for securing threaded fasteners. There are specific types of thread-locking fluids, often referred to as thread lockers, which are designed as anaerobic sealants to be applied to threaded fasteners to prevent loosening, leakage, and corrosion.
Regarding the second statement, it is true that fumes from an anaerobic sealant can be harmful to an O2 sensor. This can occur during the curing process where the anaerobic sealant's fumes may come into contact with the sensitive elements of an O2 sensor, potentially leading to its malfunction. It is crucial to prevent any sealant fumes from reaching the O2 sensor during automotive repairs and maintenance.