knock sersor on 2003 Ford F-250 Super Duty

how do you check if a knonk sersor is bad do you need to take off the maniflod to do it dom1967@comcast.net thank tou

by in Warminster, PA on March 02, 2011
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2 answers
ANSWER by , March 03, 2011
Standard knock sensors can be tested by tapping near the sensor and checking timing on a scan tool,Or you may hear an rpm change.Pezoelectric knock sensors cannot be tested the way.
ANSWER by , March 02, 2011
The only method that I know how to diagnose a knock sensor is to monitor the sensors output with a capible scan tool while operating the vehicle. I habe seen failures of the knock sensors from a rodent that has crawled under the intake and chewed into the wiring.