Hey all, so my family has a Honda odyssey that's been sitting since January due to a bad alternator. One mechanic said that a bad valve cover gasket was getting oil on the alternator which caused it to stop working, so he put in a new valve cover gasket, cleaned the alternator from all the oil and said it should work fine now. The car still couldn't run by itself, so 2 months later, we got another mechanic who said the alternator was bad. He charged the battery, and then put in a new alternator and finally the car ran after half a year of sitting. However, he noticed that the car was running at 2k rpm only when it was in park (when I put it into other gears, it idled a little below 1k rpm). This was very odd because before January it never ran at 2krpm or anything like that. The mechanic said it could be a vacuum leak caused by the previous mechanic's valve job or maybe an animal chewed through something because it sat for so long. The weird thing about all of this is that I drove the car for about 20 minutes the same day it was fixed, and then parked it until the next day when I turned it on and it no longer was running at 2k rpm, it was running at just below 1k rpm. What could have caused it to be running at 2k rpm the same day it was fixed, but then fixed itself the next day? I just want to make sure if its something I should be concerned about or not. Feel free to ask any questions about my issue, thank you!