if you had a air leak in the top end of the motor from taking the TB off that was big enough to make an audible whistle you would be throwing codes
P0174 and p0171 fuel system too lean bank 1 and 2. it only takes a small pinhole leak to cause that code if you had something big enough to whistle you'd have the codes no doubt.

trust me on that i've been dealin with these codes for almost six months now. I've been trying to sell the truck but no one buys a vehicle with a CEL on dealers have had it almost ten times to no avail.

 

i have no codes, but it seams weird that i never heard the sound until i cleaned the TB, i've always had the normal swishing sound from the CAI but never a whistling until now that's why i'm confused about it and wondering if there my be something that i'm not seeing

 

Ok, i've had my truck since new.. I installed a CAI and a TB spacer at the same time and of course there was a whistle. Well a year later i decided to take off the spacer and clean the tb because there was alot of carbon build up on the inside of the tb. After cleaning it i took it down the road. There was a faint whistle when i was getting into the gas a little. I almost doubted myself that i put the spacer back on. I checked and it was off. It really only did it while the engine was under a load and couldn't hear it while in park. So this may be the same situation you are going through. There were no leaks on mine because i sprayed tb cleaner around the seal of the intake tube and the tb where it mounts to the intake.

 

Well our trucks come from the factory with a 38r garret turbo. By cleaning it, you must freed the turbo wheel. Im just kidding. But just run it! Who knows its probably because the air can move easier now.

 

that's what i was thinking but wasn't sure, thanks for all the help