Uneven idle after carbon clean/new manifold?

[drval85]

Replaced manifold due to 2015 code. Cleaned the valves as well. New injector seals. Triple checked my connections. Car pulls/drives without issue. When I shift to neutral and coast/idle, the revs hang, then drop to 800. It bounces between 800 and 1200 for a few minutes, before finally dropping to 600 and idling smoothly. (600 was idle speed before swap). Got a 0171 code and a 0507, but they didn’t come back after clearing. 90% sure it’s an air leak, but I don’t see anything obvious. Has a catch can installed, so no pcv. Diverter valve is rev D, didn’t see any issue with it either. K04 with a Unitronic DV relocation, all hoses clamped tight. Intake and turbo coupler also look secure. I definitely reconnected all vacuum lines I disconnected for manifold replacement. Anywhere else I should look before going for a smoke test?

 

[Cclark6146]

mine does this too with the idle hanging and fluctuating. its annoying when Im trying to shift and it makes me look like I dont know how to drive a manual. lol. smoke test turned out fine but I didnt do any carbon cleaning or intake manifold work to it. code 0101, 2177 and 2279 keep coming back

 

[drval85]

My new manifold was leaking. Replaced again, no issues. Depending on mileage, I’d think about carbon cleaning.

 

[Cclark6146]

yes its probly due. I've never had it done and I doubt the previous owner did any kind of maintenance. it has 85k

 

[drval85]

There’s an awesome YouTube video if your going to DIY. Search for “tsi valve cleaning”. Perfect camera angles, and the guy walks you through everything.

 

[Joe_Mama]

This is on MQB but it is the same procedure.