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Engine rev

I have a 2000 Saturn SL 5-speed with 100k miles. Great mileage - 42 mpg on road. Lately it has been reving up to 3200-3400 rpm when clutch depressed at a stop light, for instance. If I then cut the engine off and restart it, it acts normal at 800 rpm. Any ideas?

Yes, Saturns are well known for this issue. It’s probably your adle air valve. Available at Autozone.

I bought a new idle air valve and installed it. The revving no longer occurs, but the “service engine soon” light continues to stay on, even tho it has been a couple weeks of driving - I thought it would reset by now, unless there is still a problem.

You need to get the computer error code(s) read and post here.
Some places like AutoZone will do it for free.
They look like P0123.

What are the codes? You may have a different issue going on. Many parts stores will read the codes for you. Try Autozone, O’Reily’s, or Advanced Auto.

Autozone read the code as PO442 and listed these possibilities: 1) fuel cap 2) EVAP canister or hose cracked 3) purge or vent solenoid defective 4) vaccum leak at engine

If you’re quite certain that the high idle was solved by the new IAC then this code is unrelated. If any high idle symptoms remain then you likely have a vacuum leak and I’d be willing to bet it is wherever the evap purges into the intake.

If the only thing you have left is the code then you might just have a bad gas cap gasket or something - though there is a system of vacuum lines that could also have leaks. Clean your gas cap, put a coating of grease on its gasket and install. See if that makes a difference.

P0442 is a small EVAP leak (0.020" hole equivalent). It can be in any, or all, of the components you named.
It takes a good repair shop to find this tiny leak. You could easily get a shop which changes parts until they get lucky. Because of this possibility (likelihood?), DON’T give any shop blank permission to change a series of parts. This article has a few more details on P0442:
You can try another gas cap. Smear the rubber with Vaseline.
If Auto Zone will erase the code, good. If not, it might take several days (with the gas tank 1/4 to 3/4 full) for the engine computer to reset and test the EVAP system. In the meantime, the check engine light stays on.