95 Saturn SC2 5sp 144k with a high idle?

[fritcr]

Some of you have read my tale of my first engine swap. It is all done and in. It now runs smooth and has plenty of power. I have a few small problems...
It "seems" to idle a little high. It it usually just under or right at 1000 rpm on the tach. Sometimes seems to take bit to come down to idle when pushing the clutch also. Just a reminder...the donar engine came out of an automatic car. I was told by a someone that the only difference was the flywheel and that all of the sensors, computer etc were the same. I cleaned the TB good before I put the engine in. I didn't take the IAC off..in fact..I'm not sure where it is. I really have not looked for it. I might try to clean that tomorrow.
Second problem is, and probably related, the service engine soon light comes on sometimes but usually not. I drove it for 1/2 hour and came to a stop light and pushed the clutch in and it idled fine for about 1 min I guess then it idled up to about 1600 rpms for a few seconds then back down and the light came on. It stayed on until I restarted the car later but never came back on that day. It has came on once before when sitting and idling in the driveway early on when I was filling antifreeze etc. I do have the old engine and all sensors etc in the shed. BTW...the ETCS on this engine was brass and looked good but I can buy a new one if you all think it could still be that. I put a new thermostate in it before putting the engine back in. Any ideas for me to try. My dad has a scan tool but only for the newer cars and it won't read this one so I can't get the code.