93 Geo Prizm with Check Engine Error 71

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I have a 1993 Geo Prizm with a 1.6L vin code 6 California engine.
The car runs perfect but get a intermitent check engine light with Error code 71.
Book says EGR Temperature sensor is out of range. This sensor is only on cars with California emmisions. The Error is allways the same code. Sometimes it happen right after I start the car while the engine is still cold and sometimes it when it 106 degrees outside and engine is running at 200 degrees.

My main Question is has anyone ever seen this error and if so what was the fix.

I am thinking it is probably not the sensor bad, but more likely a bad connection or some problem with the EGR valve.

So any Ideas.

If I left something out let me know as I am very new here.


posted by  Boatist

Thanks for the reply
My book is not as detailed as I would like and does not give a resistance check for the sensor, However it does give a expected Voltage range of the output and the Voltage input. I will check that if I can find the sensor, so far have not been able to locate. I have been hoping it will get worse so I can check it when it is failing. The one though I have had is that it is more likely a problem with the EGR valve. Maybe the temperature is wrong when the EGR fail to open fully. I Know the EGR closes as the engine runs perfect at all speeds and idle. When I find the sensor I will check and clean all the connectors along the way.
Thanks again

posted by  Boatist

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