i'm having the same issue too..except i only have like 1100 miles on my motor..mine just recently started to do this...was running fine when i had the motor swapped over....and now, it idles at like 100-200 rpm's...how do u do a vacuum leak check?

 

sometimes you can hear the leak. but take off the engine cover so u can hear clearer. listen for loud abnormal hissing sounds or use carb cleaner and spray along all the vacuum hoses. if the rpm changes then uve found ur leak. but honestly that method didnt work for me. i jus took a guess and changed the pcv vent hose cus my leak was coming from that area and the loud hiss went away. but that didnt really fix my issue on temporarily then the issue came back.

i finally had a chance to check the spark plugs out and 3 spark plug chambers had oil in it. so i ordered the valve cover from R&D and new oem spark plugs (still waiting). hopefully this fixes it. the spark plugs with oil didnt look too good. the odd thing is that my car performs like a champ jus the sputter during idling lol

 

It is normal to have a slight misfire at idle on a VQ because they are tuned so lean at idle for emissions reason. Mine has done it from day 1 (mile 8 on the ODO). Since going turbo and enriching the tune the misfire has reduced significantly.

 

mine actually is getting worse. the engine sputter is becoming more and more aggressive