Hyundai Sonata Improved MPG after reset

Recently had some work done on my car that required the exhaust control to be reset. MPG went up about 10 MPG, car ran smoother, there has also been a clicking or ticking noise I hear at low speeds that disappeared. This went on for about 30 miles, then everything went back to normal. Is that normal after engine controls relearn everything and kick in, or should I be troubleshooting for something else malfunctioning?

2015 Hyundai Sonata ~70,000 miles.


What “exhaust control” was reset? Why was this done? Was the check engine light on before the reset? If it was, wnt was the error code? Is it on now?

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Can you elaborate on that? I’ve never heard of such a thing.

This is just a guess, but perhaps the EGR was replaced.
In any event, we need clarification from the OP.

Upload photos of the work order and report.

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Thank you for the comments, apologize for being vague before, not a car guy. I had the intake runner control motor replaced and was told that when the car is reset, it takes the computer a little while to relearn things. During this period my car seemed to run much better and computed a much higher mpg. Just trying to see if that is normal or if I may have something else malfunctioning.

Wasn’t clear to me either so evidently, just cleared the memory so that the original pre sets were used to set fuel ratio etc. once re-learned it was operating from actual sensor information. If that big a difference, it would suggest to me that some sensors need attention.

How did you determine this vastly increased MPG?

Sure this is not a placebo issue? I can’t see an intake runner making that much difference.

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If you were going by the dash readout then you don’t really know if you mpg increased . If you check it the old fashioned way for 2 or 3 refills and it gets what it should then you do not have a problem.

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But th op said after 30 miles it returned to the old results again. Not enough time to check for mileages the old way.

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It is unrealistic to determine gas mileage in 30 miles. If you were looking at the mpg display you had bad data. It sounds like sensors were reset and it took 30 miles to find their normal state.

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To answer your question. if the battery was disconnected, in which it probably was. it will take a while for the vehicle to reset / relearn. a lot of cars take longer than 30 miles to relearn /reset everything though.