Which of the following could cause an IM240 test to fail a vehicle for high HC while a shop’s concentration sampling gas analyzer might not be able to identify the source of the hydrocarbons with the...

Which of the following could cause an IM240 test to fail a vehicle for high HC while a shop’s concentration sampling gas analyzer might not be able to identify the source of the hydrocarbons with the probe placed in the tailpipe?

A. Fuel line leak near the front of the vehicle

B. Antifreeze leak near the front of the vehicle

C. Evaporative/canister purge system hoses Disconnected

D. All of the above