E90 330d increases emissions mystery p3263

[Danxr46]

As above my car suffers this when slowing right down and turning a corner but will go off after a few days.

I’ve replaced a lot of items and the p code points towards the egr system.

Anyone else had any experience of this and also knows where can get hold of download for bmw software online?

Many thanks

[Elliot2000]

that is a fault describe air mass is less than it should be .

Can be caused by lots of things like egr sticking open, coked up inlet valves, swirl flaps coked up, swirl flaps not working, blocked air filter, etc

Is it an m57 or n57 you have?

[Danxr46]

It’s m57.
Egr is new and mass sensor and had a reset and was fine at garage.
Only thing haven’t had done which some suggest is changeover valve as that is actually for egr system and not pressure converter as that’s turbo but someone mentioned vacuum goes to engine mounts?
I don’t have swirl flaps fitted as blanked off. I really need to fine somewhere that has an easier download of INPA etc