Yeah, mine has done this as well. I noticed it the first time at 400 miles. It has never bothered me, cause it only happends if i rev the engine high while in no gear. Then when its about to start idling at 1krpm it drops to 800-900 for a second or so then goes directly back up to 1krpm.

 

I have heard that some stock intakes have a special coating similar to k&n filter oil, that is there to catch dust and small particles that pass thru the filter. My beater(F-150) has a sticker on the throttle-body that says DO NOT CLEAN. I have looked inside and it was somewhat dirty, I am thinking about cleaning it someday and recoating it with oil. I am not sure how much this helps, but should catch more than a dry/un-oiled intake.
p.s any thoughts welcome

 

You should be careful what you run through your engine. You could damage your cataclysmic converter. Make sure you use stuff that says its compatible. I suspect brake cleaner is not. But newer carb cleaner sprays probably are OK.

 

Simply reducing the amount of hot air in the engine bay did the trick for me. <shrug> I don't see how this could work, but if you see results, good on ya.

 

As I sat here and read this thread, one thought kept surfacing: when the cleaner was sprayed into the throttle body, it must have cleaned the MAP sensor that is mounted on the top of the throttle body. I wonder??????

I agree with the possible "cataclysmic" results on the "catalytic" converter if you use brake cleaner. I would stay with carburetor cleaner, which should be safe for your catalytic converter