All of the following statements are true EXCEPT:
A) to quickly evaluate compression, listen during cranking for an even rhythm and then for a smooth idle.
B) an EGR valve is open at idle during normal operation.
C) when an EGR valve is opened by a vacuum pump, the engine should stumble and run roughly.
D) a vacuum gauge is easy to connect and can be used to qualify engine condition.

Question

Quizplus · Accepted Answer

The EGR (Exhaust Gas Recirculation) valve is typically closed at idle and opens under certain driving conditions to allow exhaust gases back into the combustion chambers to reduce NOx emissions. If it were open at idle during normal operation, it could cause the engine to run poorly or stall.

All of the Following Statements Are True EXCEPT