Help with RPM Fluxuation

[jsmith14]

I have a 2004 Z71 Chevy Tahoe with 115K miles. I recently had the transmission rebuilt. There really has never been major issues but I recently moved to the Washington, DC area. Now when it is cold (especially in the morning) I am hearing a whooshing sound and my RPM's go up then immediately fall back. I am not sure what it could be. I had someone tell me it could be a sticking valve. Any help would be appreciated.

My RPM was also fluctuating, i changed MAP, TPS and all, in the end it was actually the oxygen sensor that needed to be replaced. I visit my repair shop on Washington that tip on the problem. Changing O2 sensor fixed everything. you can look for some other Washington auto repair on your location that near you.