# 2019 Infiniti QX50 CVT: Sudden drop in MPG + change in engine noise — no codes

**URL:** <https://community.cartalk.com/t/2019-infiniti-qx50-cvt-sudden-drop-in-mpg-change-in-engine-noise-no-codes/178452>\
**Category:** Maintenance/Repairs\
**Tags:** nissan, noises, transmissions, engines, infiniti\
**Created:** [August 3, 2021, 2:40am UTC](https://community.cartalk.com/t/2019-infiniti-qx50-cvt-sudden-drop-in-mpg-change-in-engine-noise-no-codes/178452 "2021-08-03T02:40:13Z")\
**Posts on this page:** 2\
**Page:** 2

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**Author:** ![thegreendrag0n](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/thegreendrag0n/32/9265_2.png) [@thegreendrag0n](https://community.cartalk.com/u/thegreendrag0n)\
**Post date:** [August 4, 2021, 2:18am UTC](https://community.cartalk.com/t/2019-infiniti-qx50-cvt-sudden-drop-in-mpg-change-in-engine-noise-no-codes/178452/21 "2021-08-04T02:18:50Z")

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> [@George\_San\_Jose1](#):
>
> An exhaust system leak prevents the engine computer from providing the correct air/fuel ratio.

more likely than not it would set the CEL illuminated

I think the best is to consider using warranty if car has any of it left

if local dealer is of no help, it could help to raise to corporate level, although one has to remember that more flies can be caught with sugar than vinegar

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**Author:** ![VDCdriver](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/vdcdriver/32/48514_2.png) [@VDCdriver](https://community.cartalk.com/u/VDCdriver)\
**Post date:** [August 4, 2021, 2:13pm UTC](https://community.cartalk.com/t/2019-infiniti-qx50-cvt-sudden-drop-in-mpg-change-in-engine-noise-no-codes/178452/22 "2021-08-04T14:13:01Z")

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> [@VOLVO-V70](#):
>
> Just reset everything on the readout at refueling . That is the only way to really know what you are getting.

+1  
At every fuel stop, I zero-out the “A” miles on the trip odometer so that I can see what type of gas mileage I am getting on that fill-up. I leave the “B” miles intact, and that way I can toggle between the “A” miles and the “B” miles in order to compare my current gas mileage with my _historical_ gas mileage over thousands of miles.

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