high rpm at idle

My 2000 SL1 has been idling at 1500 to 3000 rpm when stopped. This happens at start-up. It has also began idling up when I am at a stop with my foot on the break and clutch. I have changed the O2 sensor after the computer threw a code 133 but the problem continues minus the check engine light. I wonder if it might be the ECTS. But the temperature guage does not fluctuate. Does anyone have any ideas?

My 2000 SL1 has been idling at 1500 to 3000 rpm when stopped. This happens at start-up. It has also began idling up when I am at a stop with my foot on the break and clutch. I have changed the O2 sensor after the computer threw a code 133 but the problem continues minus the check engine light. I wonder if it might be the ECTS. But the temperature guage does not fluctuate. Does anyone have any ideas?

May want to check the host from the PCV valve etc. They can wear out or come off and cause high idle. Not sure if this year has the old style tubing but my 92 SC wore out and caused high idle issues. May want to check the IAC sensor as well.

is this with the engine cold, hot, or always?
is it only while stopped, rolling, or both?
what is your gas mileage?
do you ride the clutch?
keep the clutch in at red lights or shift to neutral?

is this with the engine cold, hot, or always?
is it only while stopped, rolling, or both?
what is your gas mileage?
do you ride the clutch?
keep the clutch in at red lights or shift to neutral?


The idling-up occurs both at cold start and also when the engine is warmed up. My wife has been sitting in a drive-thru and had it kick-in suddenly and begin reving-up. She had her foot on the brake w/ it in N at the time.
It idles up at stops and it is also staying raised when pressing in on the clutch while shifting between 2nd, 3rd, 4th, and 5th gears.
We have 25 and 17 years of manual trans. driving experience with neither of us being "clutch riders".
When stopped at lights (we live in a small town w/ only 3) and travel to a larger city 1 or 2 times a week for "city driving" the car is put in nuetral.
What do you think?

The idling-up occurs both at cold start and also when the engine is warmed up. My wife has been sitting in a drive-thru and had it kick-in suddenly and begin reving-up. She had her foot on the brake w/ it in N at the time.
It idles up at stops and it is also staying raised when pressing in on the clutch while shifting between 2nd, 3rd, 4th, and 5th gears.
We have 25 and 17 years of manual trans. driving experience with neither of us being "clutch riders".
When stopped at lights (we live in a small town w/ only 3) and travel to a larger city 1 or 2 times a week for "city driving" the car is put in nuetral.
What do you think?

The problem has been fixed with a trip to the dealership and an $88 diagnostic! The ECTS and the IAC valve were both in need of replacement! My wife purchesed the parts for a total of $88.72 and I installed them this evening after work and it is idling back down below 600 rpm and idle again!

good to hear, the reason i asked about riding the clutch is somehow the programmers at saturn were able make the PCM determen how well the driver shifts then sets the idle accordingly(sets the idle higher for poor drivers to prevent draintrain damage). i used to reset the PCM almost everytime my ex-girlfriend drove, she was so crappy with a manual trans it idled above 2000 RPM!