QuestionQUESTION: The engine check light came on and the code indicated 7,1 or 1,7. Either way the light was on, then off, but lately stays on all the time. Also, I am noticing an idling issue when stopped at a light. Any ideas on the problem? EGR?
ANSWER: I think it's a code #71 which indicates a problem with the EGR system, the idling issue is related because if the egr valve is sticking open it will cause a rough idle, I would recommend replacing the egr valve and the plastic egr modulator valve that is attached to the valve.
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QUESTION: I changed the EGR and Valve modulator. The light check light stayed off for an entire day, then next day came back on and stayed that way. What should I check next?
ANSWER: Is this a 4 cylinder or V-6?
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QUESTION: is there a way to test the EGR Sensor for my 1994 4runner v6 3.0 SR5?
Answer the resistance of the sensor changes with temperature, yes there is a way to test it,here are the specs from the repair manual:
at 122 F resistance should be 69-89K ohms
at 212 degrees 11-15K
at 302 degrees 2-4K
the 212 degree temp is not a problem just put the sensor in boiling water, the other temp readings would require some other method of controlled heating of the sensor, the manual states to use oil and put the sensor into it and vary the temperature so it seems that a deep fryer would work very well if you want to go through all that.
