1991 Nissan 240SX Question on EGR and knock-sensor

1991 NISSAN 240SX
128,000 MILES • 4 CYL • 2WD • MANUAL
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SHASHANKP
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Since the Check Engine light comes on I retrieved the code from OBD as 32 and 34.
The Factory Service Manual for the car states:
32 - EGR function - EGR valve does not operate. (EGR valve spring does not lift).
34 - Knock sensor circuit - The knock sensor circuit is open or shorted. (An abnormally high or low voltage is entered).

I need to know if it really could be that both EGR and knock-sensor circuit have problems or fixing one should get rid of the other problem. Also if such is the case then which problem needs to be tackled first !!!

Thanks
Mar 24, 2009 at 5:59 PM
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ZACKMAN
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They are two different circuits, entirely. But I would fix the EGR first. Reason being that when the EGR is malfunctioning, your entire engine is out of "sync", your knock sensor may "misdiagnose" the problem as "knocking" in the engine.
Mar 25, 2009 at 1:19 AM