Idle problems after throttle body cleaning

[Dave2001S]

Just chiming in here. I have the exact same problem, and I mean exact, with one exception: I'm not getting a CEL. At low RPMs it hesitates and wants to stall. After warming up it seems to do fine. I removed and cleaned the air filter, throttle body and MAF sensor as you did. I can also feel occasional slight hesitation at higher RPMs during freeway driving. Checked my connections around the throttle body and everything seems to be tight. I'm going to replace the MAF sensor and see if that cures it. But I have one question for anyone who can help. When I reconnected the hard plastic air intake tube to the throttle body I noticed there was a thin O-ring that seemed to fit around the neck of the throttle body. With that O-ring in place I absolutely could not get the intake tube properly seated. Further, the O-ring didn't really fit around the throttle body snugly, but rather loosely, so I was confused as to its functionality. After more than an hour of trying to slip the intake tube back onto the throttle body neck with the O-ring in-place, I ditched it and tightened the clamp down extra securely. It seems to fit properly and doesn't move at all. However......as the problem is still with me, I'm suspicious of a vacuum leak I cannot see, or maybe that O-ring is critical and I should have it installed right. Anyone familiar with this?