I have an a6 C6 3.0 tdi, it suffers from constant turbo lag up to 3k then boosts with no issues. It also goes into limp mode, most of the time around the 2k mark going up hill or crushing at motorway speeds. Scanned with obd 11 and vcds and got this fault code. I have replaced the N75 and changed the old vaccum pipes visible on top of the engine and still same issue. Anyone have any idea of what it could be? My thoughts are it’s either actuator or turbo vanes? Don’t think it’s a boost leak as past 3k it boosts as it should (checked this with live data).

3 hours ago, louis_j23 said:

I have an a6 C6 3.0 tdi, it suffers from constant turbo lag up to 3k then boosts with no issues. It also goes into limp mode, most of the time around the 2k mark going up hill or crushing at motorway speeds. Scanned with obd 11 and vcds and got this fault code. I have replaced the N75 and changed the old vaccum pipes visible on top of the engine and still same issue. Anyone have any idea of what it could be? My thoughts are it’s either actuator or turbo vanes? Don’t think it’s a boost leak as past 3k it boosts as it should (checked this with live data).

Hi two major things to check are the EGT sensors all reading nearly the same, then the ash level in the DPF as if its way to high the ECU wont allow boost at lower speeds and only partially at higher speeds.

Steve.

1 hour ago, Stevey Y said:

Hi two major things to check are the EGT sensors all reading nearly the same, then the ash level in the DPF as if its way to high the ECU wont allow boost at lower speeds and only partially at higher speeds.

Steve.

did the pre facelift C6’s come with DPF’s? i thought they didn’t have them.