O2 sensors, multiple misfires in all cylinders problems
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The IAC is basically a controlled vacuum leak. It has no effect on the mixture.
Mixture is controlled by the PCM - by varying the injector duty cycle. It uses a number of inputs, engine temp, MAP pressure, RPM, load, O2 sensor inputs, etc.
The upstream sensors provide inputs for mixture, the downstream is for monitoring catalyst efficiency.
Mixture is controlled by the PCM - by varying the injector duty cycle. It uses a number of inputs, engine temp, MAP pressure, RPM, load, O2 sensor inputs, etc.
The upstream sensors provide inputs for mixture, the downstream is for monitoring catalyst efficiency.
#16
the truck burns almost no oil between changes. from what i read i think it the cap or bank one upstream o2 sensor. i got a small vacume leak but i think its from the filler hose to the gas tank. it rusted out a bit. i sprayed carb cleaner around all the hoses under the hood and around the trothel body and no change in idle so i dont think the leak is there. i ll check the cap tomorow
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