Hello, I have tried Googling this but not finding what I am looking for. There are two ports near my oil filter on this chevy 350 engine. The top port is open and the bottom one is plugged. All the pictures I am finding show the sensor going in the bottom port. I can remove the plug and put the sensor there bit am curious what goes in the upper port if I do. Can anyone tell me the function of the two ports? Do they do the same thing?
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Thank you for your help.