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2012 Hyundai Sonata - Sluggish after sitting

My 2012 Hyundai sonata has been sitting outside for 2yrs. The take off is very poor. What can I do? Should I add Techron fuel cleaner?

Sure, couldn’t hurt.

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Do you mean it sat for two years without being driven?

Yes, I would start it sometimes but it was not driven for as t least 2yrs.

Are you sure that’s not just normal? Sonatas aren’t exactly drag strip champions.

The gas is probably old to where it’s lost some its BTU content.

Or in other words, the old gas has less energy to provide.

When gas gets this stale, Techron nor Seafoam can do nothing to freshen the gas.

The tank needs to be drained to remove the old stale gas and fresh gas added.


Yes that is why I asked—stale gas.

There was a very small amount of gas kept in the vehicle, probably less than 3 gallons. Does not matter?

I would fill it up with fresh gas and drive it as much as possible.

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With the fresh gas then you can add a system cleaner such as Techron or SeaFoam and take is out for a long drive.

Fill it and put in some Startron in the gas , can be bought at most parts stores .

Is the check engine light on? Any stored diagnostic codes? Besides bad gasoline, sluggishness is often caused by not getting full flow due to a restriction in one or more of the systems, fuel, air, or exhaust. Checking the engine air filter and fuel filter is a place to start.