Did you just replace the IAC or clean the throttle body as well? The IAC can cause idle surging, as can a leak in it's gasket or the PCV hose connecting to the throttle body. Maybe MAF also, but since you replaced the IAC I would recheck the work done in that area.
Vince and Susan
2011 Tiffin Phaeton 40QTH (Cummins ISC/Freightliner)
Flat towing a modified 2005 Jeep (Rubicon Wrangler)
Previously a 2002 Fleetwood Pace Arrow 37A and a 1995 Safari Trek 2830.