A.Presence of free carbon in exhaust
B.Presence of carbon monoxide in the exhaust
C.Presence of oxygen is the exhaust
D.Presence of nitrogen in the exhaust
E.None of the above
A.Presence of free carbon in exhaust
B.Presence of carbon monoxide in the exhaust
C.Presence of oxygen is the exhaust
D.Presence of nitrogen in the exhaust
E.None of the above