Long story short..I cleaned out my throttle body and spinned the butterfly open to clean inside. afterwards, my car idles erratically and rev hangs like crazy. 2007 Civic Si. I tried the idle learn process 4 times already and am convinced that it's not it. I'm not sure what else to do.

 

similar thing happened to my jdm fd2 after i had left it in my garage and off the road for a couple of months, the battery went flat while it lay up, so after charging it and starting the car and the revs were all over the place on idle and while driving they would be hanging and even jumping between 250rpm-500rpm on gear change, also anytime i touched anything electrical on idle the revs would jump more than usual, it took couple of months to sort out but it simply just fixed itself one day while driving on the motorway and has been perfect ever since, i hope this is of some help and also that it doesn’t take that long to resolve for you mate.

 

You have a drive by wire right? You are not supposed to manually open the throttle plate. Have you done a computer reset?

Will the throttle plate close back on its own?

 

have you tried driving the car? if not i would drive hard do a few wide open throttle pulls and then try doing the idle relearn. the iac most likely has cleaner still sitting in it.

 

The idle learn procedure must be done so the ECM can learn the engine idle characteristics.

Do the idle learn procedure whenever you do any of these actions:

Replace the ECM

Reset the ECM

Update the ECM

Replace or clean the throttle body

Disassemble the engine or the transmission

NOTE: Erasing the DTCs with the HDS does not require you to do the idle learn procedure.

Procedure
Make sure all electrical items (the A/C, the audio system, the lights, etc.) are off.

Reset the ECM with the HDS.

Turn the ignition switch to ON (II), and wait 2 seconds.

Start the engine. Hold the engine speed at 3,000 rpm without load (in neutral) until the radiator fan comes on, or until the engine coolant temperature reaches 194 °F (90 °C).

Let the engine idle for about 5 minutes with the throttle fully closed.

NOTE: If the radiator fan comes on, do not include its running time in the 5 minutes.