A vehicle failed an emission test due to high carbon monoxide and hydrocarbons in the exhaust gas. What could be the cause?
A) Overfilling the fuel tank
B) Saturated EVAP charcoal canister
C) Either A or B
D) Neither A nor B

Question

Quizplus · Accepted Answer

Overfilling the fuel tank can cause the fuel to enter into the EVAP system, saturating the charcoal canister, which leads to higher hydrocarbons in the exhaust gas. Therefore, either A or B can be the cause of high carbon monoxide and hydrocarbons in the exhaust gas.

A Vehicle Failed an Emission Test Due to High Carbon