High rpm at idle

First, I am new to the forum so thank you for your time!

I am trying to diagnose a problem on a 2001 Impala LS with the 3.8. I have been having issues with the idle on this car. Start the car, idles fine for about 3 seconds, then jumps to around 2000-2200 rpm, then sorta moves up and down from 2000 to 2500. Also seems to hesitate and sorta sputter when it's given any sort of gas. Mass air flow sensor MAF already replaced...

My only thought, mainly from reading all sorts of stuff on the web, is either the O2 sensor or the MAP sensor. Any ideas? Or is it possible that when the MAP sensor was replaced, they could have done something with a vacuum line? Other people have suggested that this is a vacuum leak somewhere. Can anyone tell me, or show in a picture, where the MAP sensor is actually located ont he car?

Again, thank you for any advise!

Welcome to AF. What was replaced the maf or map? Did it start after either one of these were replaced, any CEL? Have you had a full scan done to look at sensor inputs and iac activity? Why were these parts replaced?

sounds like the idle control sensor....

The MAF sensor because the temp sensor was reporting zero's... It was scanned at that time, and MAF replaced. All was well for about a month, then this idle issue began.

Not sure what "CEL" is???

I haven't had it scanned yet because I am afraid to drive it at this point. I plan to have it done, but I was hoping it would be an issue someone has seen before, at least to get the idle down before I drive it to get it scanned. I just don't want it to overheat or cause any other issues.

CEL, check engine lite, it should not overheat for what your are stating. The maf has no effect on temp readings, don't understand the correlation being made as far as the maf replacement is concerned.

Oh duh hahaha! Was thinking SES light for that. But no it's not on now. It was on though, so I had it scanned. It showed the MAF was bad, but also replaced the temp sensor and the lower O2... the one right behind the cat.

I found a vacuum leak and it is idleing normal now. Thanks. Another issue found, will post another thread for that issue.