E90 320d cat/DPF/EGR/swirl flaps et al

[hagu13]

After a few years out of BMWs I needed an econobox for long distance commuting and decided on the E90 320d (2006 so M47 I believe)
Was really enjoying it until I decided to change the air filter last weekend. I'm reasonably proud that I achieved it with the engine still in the car.

My fuel consumption on the open road (500km one way commute) is around 5.8l/100km. I'm a fairly economical driver and can usually beat manufacturer's quoted figures quite easily, so I'm feeling there's a potential issue here. I was getting close to that with my E46 330d's
Diagnostics are clean, injector balances 0.0 to 0.1, no smoke

By now (188k) it could probably afford to lose the cat. I'd like to do EGR and clean the inlet too.
My questions:
Does this model have swirl flaps?
Can I decat and de-EGR without mapping? I know mapping will give more power but it's a commuter and I'm not bothered about that. I have other cars for speed.
Any other suggestions why it's a bit thirsty?

 

[Solo Man]

Ok, my instinct says either the egr thermostat is staying open or the main thermostat is staying open. In other words, either the one or the other or both are not functioning. Fortunately for us the BMW thermostats of the more mordern models stay open when they break. I would first replace the egr thermostat as that is cheaper and more easily accessible. that is usually the reason for the increased fuel consumption. Your model still have the normal swirl flaps which i suggest you immediately remove and plug. You can decat and de-egr without mapping. Some cars will show a yellow engine light when doing the egr delete but some don't. I have driven two of my cars (E60 and E81 120d) with the engine light on after doing the egr delete with no problem. I would do the mapping or chipping to increase torque but that is just me. You can check the engine temp by going into the on board computer but you will have to google how to as i cannot remember out of hand. If you remove the egr thermostat and you can blow through it when it is removed it is stuck in the open position and you will have to replace it. I have used the ones from Goldwagen as they are similar to BMW oem with just the BMW emblem filed off.

 

[hagu13]

Thank you

I have a fake Delphi so I can check temps on a drive. And will look at the EGR thermostat. Surely if I blank EGR I can also just blank the EGR thermostat rather than replacing it though?
Finally got a break from work coming up so will attend to the rest