Also, make sure the high idle isn't being caused by something simple like the gas pedal, cable or throttle aren't sticking, keeping it from returning to normal idle.

i think i got all the above areas with spray and nothing happened. i took off the intake and sprayed in the throttle body. i also looked at the air filter and it didnt appear to be clogged.

for the fun of it i disconnected the hose on the right side of the valve cover and nothing happened. not that it was supposed to? the pcv short hose was hard as rock so i didnt wanna move it. the brake booster line was very 'dangly' but it appeard to be ok on both ends and i sprayed what i could.

i also moved the throttle manually and didnt notice any hangups.

IIRC the rev limiter only "engages" (electronically) if the VSS (vehicle speed sensor) detects a signal of <3 mph and high/rising rpms, and then prevents the engine from redlining and destroying itself.

So that 4K rpm condition should never occur unless you are under 3 mph.
Is this the case? It is not relevant to the PCM WHY the rpms are so high at such a low vehicle speed--it just does as it's programmed.

Wonder if oil got down there into the VSS wiring (I think it's mounted in the side of the tranny case but I can never remember which hole in the case is the VSS and which one is for the output speed sensor--they are installed kinda mirror image like.

Does it ever change from normal idle to 4K rpm just literally sitting there idling?
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Did you ever run this car for check engine codes? Is the light on?
I just reviewed the thread and none of us asked and you did not say yay or nay.
If the check engine light is on then we may be on an extended goosechase to nowhere.

Please get the codes run even if the light is off; you may have stored pending codes that have not yet turned on the light.
Autozone etc will read codes for free.

it definitely does it when standing still (going to 4K) but she cannot say certain that its the only time. but pretty sure its only at a stop.

i have an autoxray 7000 so will scan for codes then.

will tell her to keep an eye and be certain when it does it

she stated this high idle didnt happen all week and she had her normal schedule with everything and actually bit more driving. maybe my spraying fixed it? keep fingers crossed.

Maybe you freed up part of the throttle body or cable mechanism such that it no longer sticks.

However, the valve cover gasket still requires attention. Don't let it go....

well now we have this:

occasionally when gf pushes in the clutch to come to a stop, it revs up to 2000 but once she is stopped, it (so far) has always died down to normal idle.

You may be looking at the Idle Air Valve, but if I'm not mistaken, this is a "learning" sensor and will adjust if a low idle condition existed for a while. Maybe after a week, that will fix itself. Some one correct me if I'm wrong. My 01 SL1 will idle at around 1300 while coasting off the off ramp in neutral, but then come down to 700 rpm at a stop. Idle is affected by the engine coolant temp sensor, and the throttle position sensor too. Quality AC delco parts make a big difference in these cars as well.

/Not trying to be nitpicky, but I don't really consider coasting on an off ramp as an idling situation.

Idle to me means rpm with car at rest w no load on engine. (0 mph, neutral.)
The PCM takes the vehicle speed into account when you put it into neutral so that if you re-engage the clutch at some point while slowing down, it will not result in a huge jerking motion upon reengagement because the rpms are kept close to wbat wojuld be expected if you did re engage the clutch.

Idle rpm is indeed affected by engine temp, thus the ECTS reading, the throttle position sensor output signal, the air/fuel mixture and the proper operation of the IAC valve.
I think it can be removed and cleaned but it is very delicate.

You aren't nitpicking and you are correct. The reason behind my "off ramp" statement was to let the OP know that the PCM will let the rpms hang if you are still moving and in neutral. My choice of using the word idle was just indicating that my foot was off the accelerator. Its all good.