Which of the following is NOT a major emissions-related component that may require repair?

The air conditioning compressor is not typically considered a major emissions-related component. Its primary function is to circulate refrigerant and provide cooling for the vehicle's climate control system, which does not directly impact the vehicle's emissions output.

In contrast, the catalytic converter, oxygen sensor, and fuel injector play crucial roles in managing the vehicle's emissions. The catalytic converter is essential for converting harmful exhaust gases into less harmful emissions. The oxygen sensor monitors the amount of oxygen in the exhaust gases to optimize fuel efficiency and emissions control. Fuel injectors ensure the correct fuel-to-air mixture is delivered to the engine, which is vital for reducing emissions.

While the air conditioning system may have its own performance and efficiency concerns, it does not directly influence the vehicle’s emissions system, making it an unrelated component when discussing emissions repairs.