well i have asked this question before and really didnt get a straight answer from anyone so here i go again.my car(auto) does this wierd thing when im coming to a stop. when im coming to a stop i can see my idle go up and down a couple of times and settle at the normal idling speed on drive.also it idles high(aroung 1200-1500) if i let the car sit for a while eaither at a stop light on drive or on park for a while. few months ago i had a MAF Sensor replaced too. did any of you guys had this problam before and if so what is the problam i am asking from you guys is bcus my mechanic really dont know whats wrong and you guys seem to have more knowledge.

p.s. before i had the MAF replaced it did 50mph at 1500rpm and now it does 50mph at around 1800rpm.

all my modding will be stopped till she is back to normal too. :-

 

It could be a vacuum leak from a cracked hose...but I doubt it.
This sounds like a gunked up or bad Idle Air Control Valve or one of the connections to it. You should also check to make sure your fast idle cam is fully rotated out of the way with the engine warm.


BTW, the MAF will have little or actually no effect on what RPM's you run at different speeds. If you are truly running higher RPM's at freeway speeds change your ATF. If that doesn't help then have it checked by a technician. Mine runs about 1800 RPM's at 50 MPH.

 

^^^^^ thank you. i decided to leave my car at home as much as possible till im done with finals. then i will do the idle re-learn (as n3958 told me)and also i will check what you said.
btw, i did change the tranny fluid, actually i dropped the pan and changed the filter too but, this problam didnt occur after that it was happening way before but wasnt really bothering me much. but if your car does 5omph at 1800rpm's then i guess its normal.