I've been told that an exhaust leak with aftermarket headers can cause idle surge and weird idling. The claim was that exhaust air is pulled back up across the O2 sensors between pulses. I guess this is not an issue with the OEM manifolds since the cat is between the precat O2 sensors? I kept burning through gaskets so I just had some V-bands installed.
But my idle still surges a bit but not terrible. I still think the tune is not totally correct.
I plan to get Eurocharged to do my tune in the near future. Remote tuning was such a PIA.
2013 F30 328i - Melbourne Red
2011 E90 M3 - Monte Carlo Blue
2004 E46 M3 - Imola red
Last edited by bigjae1976; 01-02-2013 at 07:57 PM.