Q: Engine revs way up when started, then behaves normally. If the car has recently been started, it doesn’t have this issue.

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When the engine is started for the first time each day, the engine revs way up, and the RPMs gradually go down to normal idle speed. If the engine has recently been started and the engine hasn’t completely cooled off (I.e, it’s been sitting in a parking lot for 30 minutes) it starts normally. I know that the car is supposed to do this until the engine reaches operating temperature if the weather is cold, but it behaves this way even if it’s a balmy 80 degrees outside. My very amateur diagnosis is a faulty cold start sensor, but I want some input on what other culprits might be (or if I’m wrong altogether.)

My car has 82000 miles.
My car has an automatic transmission.

It is normal for the engine rpm to go up to about 1200 to 1400 rpm when first started and then comes down gradually. This is for emissions during cold start and considered normal. If you feel it is not normal then I would recommend having the computer tested for stored codes and if no codes then you may have a sticking throttle body when cold and may need to have the new start stop recall done on the vehicle.

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