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Q: My check engine light came on and the it was diagnosed as op128 so I got gas screwed on my cap and my light turned off how is this

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So today my check engine light came on and I took it to auto zone and they said it was OEM OP0128 and it was affiliated with my coolant level and then I started to drive to the shop but need gaswhen I got gas I got back in my car and started it up and my check engine light had disappeared I was wondering how this could be if it was diagnosed as a coolant issue

My car has 108383 miles.
My car has an automatic transmission.

First, a trouble code P0128 does have to do with coolant, but it is not the level. This code is set when the relationship between the coolant temperature sensor and the intake air temperature sensor don’t increase at a predetermined parameter set by the computer.

So what is being expressed by the code is that the computer is seeing readings outside of the normal operation. This could be caused by a failed sensor, a faulty thermostat, coolant level is possible (but unlikely), or possibly any number of other possible causes. It would be best to have a certified mechanic diagnose the Check Engine Light in person so that this can be corrected properly.

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