New LS1 Owners - Newbie Tech - TB Issues

Just put a Shaner throttle body on this weekend that I had picked up used. When I first started it up, it sat at 1000 rpm for a while but eventually fell back down to ~800. Now it won't even do that anymore, it just stays at 800. At first I thought it was just taking a while to get to idle, but now it doesn't go back to the same idle at all. I can correct this by adjusting the idle screw stop correct?
I'm also getting a service engine light now. Haven't gotten it scanned yet, but what is it most likely? I thought about if I didn't have the plate centered and if it would catch when it swings shut, but I made sure I didn't hear any contact sounds before it snapped completely shut before I put it in. I'm almost positive that's not the issue, so what else could it be? I've reset the pcm once and it still came back. This TB also came with sensors and I have those on now, I might swap them for my original sensors and see if that takes care of it.

Man the forum is slow today. Any ideas on what would cause the SES light other than if the blade was catching?

when i first put my bbk tb on my bird idled at 1000 rpm because it was just resetting the computer because there was more air being sucked in but it never set a code after that it has always idled at about 700 rpms

I figured mine would eventually work it's way back down to the stock idle but it isn't. The code I'm throwing is for "high idle control". Basically it's idling 200 rpm ofr greater than the stock tune wants it to and so it's throwing the code. I'm going to try adjusting the screw and see if I can drop the idle a bit. That or I suppose it's possible the guy I bought it off of drilled a larger hole for a cam, if that's the case I can just use the plate off of my stock TB.

Do you have a friend with autotap. You may want to close the throttle blade some and then disconnect the Throttle Position Sensor and replug it back it for it to zero out. If you have autotap, you can check your IAC counts. I'm not sure what a good number is, but do a search. It's possible that that particular throttle body has had the bypass hole opened up too much on the throttle body blade. The only other thing, is I had trouble with high idle, so I took the IAC valve out of the throttle body and cleaned it up really good with carb cleaner. Fixed my high hanging idle problem.

Yeah, got the blades both off, the new throttle body blade has a larger hole for the bypass. So that is where the extra air is coming from. I'm putting my stock blade on thenew TB and that should fix it.

The stock blade fixed the problem. It settles down to idle at ~750 now. That should cure the engine code problem.