Intermittent high idle solved,duh!!!!!
 

1-2 weeks After a minor rearended accident, bumper not yet repaied,estimated by dealer to be 450$ canadian only,my car developed a high idle,intermiteently.Looked at this newsgroup,found out re icv,throttle postion switch etc.
Took it to moonlighting mb mecahnic,who looked at my car at an incline.Idle not too high around 1000.He disconnected icv,same,no difference.
He then cleaned some contacts under the air filter housing and tested three prongs with electrical instrument and moved the throttle linkage from side to side.Reconnected.Idle 800.
I thought fine.problem solved.Mecahnic declined money but I gave him some anyway.
Nest morning,high idle again.1000 in d,1500 in park.
Turned out the rubberised winter Pantsaver mat was pressing on the gas pedal intermittently causing high idle,must have moved slightly forward during the accident and intermittently pressing on the gas pedal.inspecting at an incline in his driveway,the mat will slightly fall back and relieved the high idle a bit.
Lesson learned.