What other service did they perform? And, what year is your Civic?
Since they adjusted the valves, that alone could affect how much air/fuel the engine takes in (I think). They may have been set too low, so there wasn't as much air/fuel getting into the engine as Honda recommends. I don't really know how MAP sensors work, that's just what it sounds like to me. It could definitely be something else that they adjusted though.
And, many newer cars have a 'learning' procedure - whenever the battery is reset, the ECU changes how certain systems react in the car based on your driving. Your ECU might just still be trying to find the right settings.
Another thing to check is tire pressure, if you normally keep your pressure higher than the car recommends. Many shops just change the tire pressure to whatever the car says, even if it's already higher than it.
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