Cold start emissions reduction is being discussed. Technician A says that a strategy to reduce them is to delay the PCM going into close loop mode. Technician B says that an applicable strategy is to retard ignition timing during engine warmup. Who is correct?
A) Technician A
B) Technician B
C) Both A and B
D) Neither A nor B

Question

Quizplus · Accepted Answer

Technician B is correct because retarding ignition timing during engine warmup can help the engine reach its optimal operating temperature more quickly, reducing cold start emissions. Delaying the PCM (Powertrain Control Module) from going into closed loop mode would actually increase emissions, as closed loop operation allows for more precise control of the air-fuel mixture based on feedback from the oxygen sensors, improving efficiency and reducing emissions.

Cold Start Emissions Reduction Is Being Discussed