Just bought an '00 SSEi (36K miles)last week,....it seems to run fine....but it has a noticable rough idle and it usually settles 'down' to a 900 rpm idle speed(in Park/Neutral,A/C off)[my '97GTP (67K miles,original plugs/wires)used to idle smooth as silk and always at 750rpms].
Does anyone have any ideas as to why the rough and high idle???...bad plug/*??,bad wire/*??...EGR valve??,...dirty throttlebody??No engine codes are showing up.I want to take car back to the dealership to have them check out the condition(before my 90 day Warranty ends),but also want to try to pinpoint the cause of the condition.Thanks for any insight,info,and feedback

http://www.warrantygold.com/

This should help you out for the next 3 years!

Talk to Chad Mikels ext. 4257 I think and he will kindly assist you. Tell him Steven from Chicago sent you.

...already bought the $50 Deductable,Major Guard,GM Protection Plan for 3 years/36000 miles,when I bought the car,....cost $1800,covers the engine,transmission/trans-axle,FWD assemblies,fuel system,engine cooling system,heating and A/C systems,electrical-computer-audio systems,braking system components[not rotors or pads],front and rear suspension,steering system,high tech components(HUD,DIC,etc,etc),seals and gaskets,and Safety assemblies(Stabili-Trac,Traction Control,Air Bag systems)along with Roadside assistance and Alternate transportation,.......and within the next 3 years,mechanical,electronic problems will most likely crop up.One or more big-ticket fixes under this warranty will pay for itself,no doubt.
I'm,right now,just looking for diagnosis/repair of anything that could be wrong/out of tune in the car,under the dealership'*[State Law] normal 90 days/4000 miles used car warranty period.Just added a bottle of injector cleaner,on my own,to see if the rough idle condition will clear up.........