I tried to search but didn't seem to find anything. I recently installed the thermal intake spacers from nwp engineering. car is definitely quicker and sounds nicer. problem is, when I'm stopped the car has a funky idle like the engine shakes (not too too violently) and the RPM needle kind of bounces, very very slightly. But I can definitely feel the shake of the engine. As soon as I press the gas to go, lightly or hard, it stops right away and the car goes smooth as butter. IACV is freshly cleaned, as is the EGR and throttle body, new spark plugs, new knock sensor, and some other maintenance / cleaning things while the spacers were being installed. It's not so terrible that I cant live with it, but I jus don't know if anything is messed up or what not. anyone have thoughts?

 

I can't see the spacers causing a problem. Check to make sure you didn't leave any hoses disconnected and make sure the manifold is torqued back to spec.

 

the manifold is definitey torqued back to spec, and I'm pretty sure the hoses are all connected, but I'll re-check...

 

Sounds like a small vacuum leak. Spray some carb cleaner around all the spacers that you installed and see if the idle smooths out. If it does you've found your leak.

 

yea, no vacuum leak as far as I can tell.

 

Did you check electrical connections also?

 

I did indeed. At first, the throttle position sensor was slightly unplugged which was causing extremely difficult shifting and idling, fixed that, then it was smooth, then just this morning it started. I can definitely live with it if need be, I jus wanna make sure its not screwing anything up in the long run... thanks for the help by the way!