08 legacy idle rpm's after head gasket replacement

[markwv]

hello all i just replaced my head gaskets on my 08 legacy 2,5i after getting done and starting the car the the idle rpm's seam low and when i shift into gear the rpm's drop to under 500 and the motor starts to shutter but then does back up and steady's out at the low rpm, other than that it runs and drives great, i checked the vacuum lines and found none leaking , and i know you can't set the idle speed with the electronic throttle body , any idea on what it may be ?

thanks

 

[brentim]

Try cleaning the throttle body and MAF sensor.