Cleaned EGR valve, now having problem with sudden drops in RPM's while idling

[Tsenru]

Hey guys, so I was replacing my rear motor mount the other day and while I had the intake hose and battery out of the way I thought I might as well do a long overdue cleaning on my EGR valve. I removed it without a problem and cleaned it, but now that it's back on my engine occasionally dips suddenly in RPM's and shudders while I'm idling. No problems whatsoever while the car is moving.
I checked the air hose to make sure it was snug and not cracked or split (which has happened to me before) but couldn't find anything wrong.
Any idea what the problem could be? If the spring and valve inside the EGR valve aren't lubricated enough could it cause this problem? I didn't have anything to oil it with while cleaning it but it seemed to move smoothly while I was working on it. Other than that, all I could think was that maybe I didn't get it on tight enough, but it certainly feels snugly in place. I don't need to apply any sort of sealant to the gasket on the EGR valve, do I?

Thanks for any and all help.

 

[pcb]

You disconnected your battery so the ECU needs to relearn your car.

It should be fine after about 100 miles.

 

[Tsenru]

Thanks for the tip, already seems to be running smoother.

 

[ProtoPower13]

I agree. Whenever I take the EGR valve off to clean it I don't disconnect the battery but whenever you disconnect the battery and do work on your car it's going to take time for the ECU to recognize the changes you made.

 

[Tsenru]

Well, I'm also an idiot. Turns out I'd disconnected a vacuum hose off the intake manifold on accident. After driving a bit longer I got a CEL code for random cylinder misfire, which was a big cue to take a closer look. Reconnected it and the rough idle was virtually gone, what little was left went away with a bit more driving to let the computer adjust to the clean EGR valve.

Pro tip: Don't be stupid, check all hoses (even ones you don't think you touched) after working on the engine.

 

[boostracer]

What pcb said.
Even on my old Pontiac Fiero it would take about 100 miles for the car to adjust to whatever changes I made.
I cleaned my EGR valve last week and it would drop RPMs at idle sometimes. It went away after about 90 miles or so.