[335diesel]

I've loved this car since the day I got it, about six years ago. It's a 2011 M-Sport 335d, white. I've followed this forum all along and have done maintenance and upgrades based on what I find here. Usually I can find any answers I need without asking anything.

I recently had EGR/DPF delete with ECU reflash, in lieu of the more expensive route of replacing particulate filter, etc. The performance increase is amazing!

However, I think the new programming may have been too performance-oriented. I say this because when accelerating hard, the car puts out as much smoke as a large diesel pickup with aggressive tuning. So much so, that a trip from Atlanta to Orlando averaging 90-120mph resulted in my white car having a 40% gray rear end.

I sent a pic of the blackened rear bumper and decklid to my brother for advice. He's been a diesel tech for 20+ years, caveat being that he mostly works on Caterpillar equipment - which is an entirely different animal. His theory is that the fuel is not burning completely and the engine should not put out as much smoke, and shouldn't put out a visible amount unless accelerating hard. (Produces a cloud of smoke even when moderately accelerating on surface roads.)

It runs smooth, idles fine. Of course, there's a strong diesel smell - but it's not as bad as my dad's oldsmobile station wagon was when I was a kid. I don't mind keeping the windows rolled up, but I may want to consider adding a cat or something if there's a way to reduce odor that's not too expensive/problematic to replace as needed.

Is it possible that I could request that the ECU be remapped with complete combustion as the target, prioritizing this over output?

Also, is there anything I need to know other than what the stickies list out, as far as expected maintenance, or things I can replace before they fail? I'm about to take it in again to take care of any maintenance and want to do what I can on a preventative basis.

[335stoner]

check your air filter. a stock dirty filter will cause a lot of smoke... before i upgraded to a new filter i got a lot of smoke.

the back side of these cars is a dead zone for air that is why the bumper gets black..

[Yozh]

Could be tune related. Could be turbo/boost control related. If the car is in tip top shape and you don’t have any boost leaks and vacuum system for turbo control is operational then I would be looking at a tune. However, you said it smokes like a freight train. You most likely got issues with other items mentioned above besides the tune. What tune is it?

[RS DAVE]

Have you fitted a Dpf delete pipe or just had it mapped out?

[tuikku]

.
All BMW's here are Lamda-controlled.
Quite sure, that there too.
If the boost pipes leaks, lamda sensor cuts the smoke off, or at least most of its. It is its job.
But, this works only if the softw is quite a well done.
In most of cases, the tuner wants to get the ultimate power one way or another. That causes smoke.
Very often customers wants as much power as possible, if so, the hands are "tied", there got to be visible smoke to make them believe that fueling is as high as possible.

[lnxguy]

Intake will clean up a stage 2 335d nicely.

[robnitro]

Originally Posted by lnxguy

Intake will clean up a stage 2 335d nicely.

Because tuners are not really going by lambda and maf air ratios, so when you increase airflow fueling is the same and it gets less smoky.

[tuikku]

.
That's right, most of tuners "afraid" that they do not get enough power to get "highest professional" status.

Lamda- controlled system is in fact very easy. You needs only to get more air into engine and the ecu calculates automatically more fuelling and power.
If airmas controlled ecu can see risng flow => it can give more fueling.

If the pressure controlled ecu can see rising boost, it gives more fuel.