Niterdr

okay so i just recently changed my oil from a 10w-40 to a 10w-30 due to the cold weather and winter. after doing so the idle likes to sit between 2k and 3k rpms. for some reason it was acting up a while ago during summer and used to be around 1500 rpms. do you think the oil could be the problem? ive thought about it but it wouldnt make sense since its a fuel related issure. the car sounds like its misfiring but im not sure. its a ka24de-t and is run off an aem ems and has a fuel lab fpr, ams/turbo240 fuel rail, and 650cc injectors. it runs stoich even at the high rpms in idle so idk what it could be.

spark plugs? throttle body? i just dont want the motor to pop. thanks for any help!