i had this problem for about 3 years , i have underground parking and parking is tight , so turning the steering wheel hard was causing up and down idle and sometimes stalling ....so i looked at my powering steering fluid tank it was low,i topped it up and everything when back to normal ......getting to the date sept.21,2010 was me doing a google search after words...and i copy and pasted my confirmation findings .thought this information could help some one ...it was a serious problem for me a couple of years