hello, my problem is if i let my car idle for awhile (let say 10mins) after i was driving it for awhile(let say 25 - 40mins) and put it on neutral or park and idle my cars revs would go up to 1200 -1500 and one time almost 3000rpms! also i can tell when this going to happen because, my normal idling wen the car is warm is like 700rpms and if this problem is about happen it would stay at about 900 - 1000 if im on drive and at a light or something. another thing is if im slowing down to a stop from let say 40mph and and im almost at a complete stop i can hear my engine and rpms go up and down a lil bit and rpm's at cruising speeds are off too. all these problams started after i got my new MAF and i didn reset the ecu or anything bcuz, my mechanic told me that it will automaticallly do it wen you leave the car off overnight. i hope what i said made sense and will help you to figure out whats wrong. thank you

p.s. if any of you guys are from ny area and have gettogether or meets let me know.

 

Doesnt sound normal, maybe a defective MAF but if the rpm's are that high at idle you might want to check the Idle Air Control Valve (IACV).