high rpm

[skipper]

yeah i bought the inline tried to clear faults but it just came back on(the triangle)i bought a sensor for $25 is it the sensor or do i need to pull the pipe line off to see if its blocked? The code is 2554 erratic readings etc...Do i need to purchase sensor directly from Cummins? Im trying to figure out how to understand to work the inline to see the correct calibrations. No lights before putting the sensor on though...