Okay so I was running the car today doing some hard pulls. When I came to a stop I noticed that my car was idling at 1900rpm. I drove off and it felt completely normal but when I parked and put the 6mt in neutral the car was still idling at 1900rpm. I drove it about an hour later and it was back to normal but I just thought it was strange. Anyone have any guesses on this? I have an 06 G35 Coupe 6mt. I just installed an HKS replica exhaust with a resonated x pipe last week so I'm guessing this is related to the ecu adjusting to the new part?

 

Is your throttle body clean?

 

I have no Idea, i've never actually taken anything apart to look lol. The car only has 35k miles, I wouldn't think that would be an issue? Also it's never happened before and I've driven it all day today with no issue, I was just curious as to the root of the concern

 

If it is dirty it can cause idle control problems, and off idle acceleration problems (surge).
It gets sticky. In other cars I have had it seems to be more noticable when hot. Easy fix.