Technician A says when CO goes up, O₂ goes down. Technician B says at the stoichiometric point (14.7:1), HC and CO will be at their lowest levels and CO₂ will be at its highest. Who is correct?

Question

Quizplus · Accepted Answer

Both technicians are correct. Technician A is correct because when CO (carbon monoxide) levels increase, it indicates a rich fuel mixture, which leads to a decrease in oxygen sensor voltage (O₂ refers to an oxygen sensor reading). Technician B is correct because at the stoichiometric air-fuel ratio of 14.7:1, combustion is most efficient, resulting in the lowest levels of HC (hydrocarbons) and CO, and the oxygen sensor voltage will be at its optimal level, indicating a balanced air-fuel mixture.

Technician a Says When CO Goes Up, O2 Goes Down

Technician a Says When CO Goes Up, O₂ Goes Down