bank exhaust temperature without also causing fugitive fueling in such case remedial action may nevertheless be undertaken and continued until the precise nature of the equipment abnormality is diagnosed fig5 illustrates another type of exhaust temperature attribute which can be used to detect fugitive fueling when an engine is operating above the line r which shows bulk exhaust temperature versus horsepower this means that the engine is burning lubrication oil in the exhaust manifold and as a result the exhaust temperature is much higher than would be expected given the horsepower output of the engine operation at point u201c a u201d is an example of operation of an engine with an exhaust temperature greater than would be expected given the engine 39 s horsepower output as noted above it is possible with leaks in a large engine to obtain hundreds of horsepower of fugitive fueling from lubricating oil and this high amount of fugitive fueling will cause an elevated exhaust temperature before the turbocharger with the temperature being a very good indication that fugitive fueling is occurring the operating points shown in region b of fig5 were taken from a population of properly operating engines thus line r defines a family of threshold exhaust temperatures which should not be exceeded by a properly operating engine fig3 illustrates a method according to the present invention with controller 52 operating according to the method as a preface though as shown in fig2 controller 52 is.