V10 Surge on deceleration

[nazoomer]

I replaced the IAC valve due to stalling at idle in gear. That fixed the stalling but now, occasionally on deceleration to stop the engine will surge to 1200 to 1500 RPMs. Kind of scared me the first time! Any one experience this and/or have any idea what might be happening? Thank you.

[vsheetz]

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.