High idleing i have a 2004 saturn ion 1 2.2l when im driving i could feel it kick in and when i stop it wants to go.i put in nutral and it idles at 3-1/2-4-1/2 rpms.its usually at 1-1/2 rpms.i had my iac,the whole fuel system cleaned,and fuel injector wire harness replaced about 5-6 months ago.i spent well over $1000 on it. any solutions for my problem

Get a code reader and plug it in. The check engine light might not be working.
autozone etc. can check the codes for free.

You buy a 10 year old car that isn't even made anymore
and know it has issues

Do you not have a repair shop you use for many years that has
been around for decades

You need a shop to go thru the entire car & fix ALL problems
regardless of cost,not us guessing at things

Not to get up to speed could be a gas filter ,most likely worn
out & blocked exhaust converter & I could write a book

All it's issues can be diagnosed & you should spend about $1500
if ALL problems are properly tested & resolved

Now you got the entire suspension,all fluids,brakes,tires & on & on

When I buy any vehicle I put it on stands for 3 weeks min & go thru it

On a new car i spend a week a year going thru the entire car

I take brakes apart every year

I check all data every 4 months with professional scan tool software

Sounds like you have a vacuum leak. My 1997 Ford Thunderbird ran like that until I found a cracked vacuum hose.

It's probably one of two things , a vacum leak or a bad ground.

Sticking throttle. Clean and loosen the sticking parts.

may need to check your vacuum lines. Your car probably has a MAP senor (Manifold absolute pressure) so if you have some sort of leak into your intake manifold it will raise engine rpm to compinsate for the extra air.

Idle speed that high usually indicates a vacuum leak somewhere. Check every vacuum line and hose and connection you can find for loose or damaged hoses. Also make sure there's not something causing the throttle linkage or pedal to stick or be in a bind.

chek engine light on? rolling idle is usually a vacuum leak or someone adjusted the throttle plates (idle) open too far.

Sounds like a bad idle air motor (That controls idle) But you must pull compiter codes first (The computr tells it what to do)

Question? is the engine's heat normal, if not there's sensor that boosts idle when the engine is cold

If you removed the thrmostat, put it back in.FIRST

check for a vacuum leak