320d e46 decat: fume emission solution

[Brendan.184]

Hello, i recently had a complete decat done on my bmw 320d (e46) and its been giving off a lot of fumes through the exhaust. Can someone please tell me of there's a way to reduce these fumes? 

Thanks.

 

[Denzel]

Well the cat is there to hold back most fumes and by decat the fumes are able to flow out of the exhaust

Is the fumes coming into the car? Or are you worried about that puff of black smoke when you floor it ?

 

[Brendan.184]

It was actually this morning when i started it up. White fumes just kept coming and no it doesn't come into the car when the windows are up. But if i stop at a traffic light with the windows down i do get a bad smell from the fumes. Are there any alternatives to catalytic converters?

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I had it done yesterday. If that's relevant

 

[Denzel]

Ok well 1stly there should not be white smoke from a diesel, the smoke should be black suggest you get that checked but try this out 1st tonight when you park the car disconnect the the battery terminal and then in the connect again in the morning

2ndly the fumes should only be at the rear at the exhaust tip so just go back to the place you did the Decat and make sure there are no leaks where the decat was done , lastly I suggest you go get a software upgarde the decat will come into full effect with software and emissions can be set

The alternative to a cat converter is a Down pipe which is removal of the cat and then a straight pipe replacement .

My wife has a 07 320d I got the cat converter box cleaned out and replaced it is not the full effect of a decat yet certainly hold back some soot and fumes, I'm due to take the car for a sowftware upgrade when the budget is better

 

[Brendan.184]

The exhaust fumes are only coming out through the exhaust at the rear but it travels into the cabin when windows r down. I drove it around today and when i checked it when i got home i found that it was not giving off any fumes. So dont know whats happening now. Im going to try disconnecting the battery terminals for tonight as you said. So tomorrow i will let you know how things go. How much is the software that you are buying for your wife's car? Planning on doing the same but have to save up first.

 

[Dhp507]

I had white smoke when my turbo went.....pls check it out

 

[milu]

I had the same problem with my e46 320 D, on a cold start does it give smoke? I change my diesel filters.... Problem seems to be gone, else buy a bottle of injector fluid, with a full tank poor it in, and take a long trip so it can work it through the engine.

Hope that helps :=):

 

[ernest maurice]

hi guys
just wanted to know what a decat is all about. I also got a 320d and the only mod I did was taking out the swirl flaps. what benefits will I get if I do it? my car has a light sky bluish smoke when I floor it while the engine is not yet fully warm, is it s bad sign?

 

[Kish2604]

To the O.P... Doing a decat won't cause any necessary harm to your motor, however something does come to mind, some exhaust shops use off the shelf silicone sealer (some of these are known go handle 500deg before burning) when bolting together flanges and gaskets etc, the excess burns of with a horrific smell and white fumes out the exhaust, it took mine a day and half to burn of and the smell to stop.. +-120km of driving..
This could also be your culprit for the white smoke and fumes you experiencing..

Anyways its just a hunch... Let me know how wrong I was later...

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Ok well 1stly there should not be white smoke from a diesel, the smoke should be black suggest you get that checked but try this out 1st tonight when you park the car disconnect the the battery terminal and then in the connect again in the morning

2ndly the fumes should only be at the rear at the exhaust tip so just go back to the place you did the Decat and make sure there are no leaks where the decat was done , lastly I suggest you go get a software upgarde the decat will come into full effect with software and emissions can be set

The alternative to a cat converter is a Down pipe which is removal of the cat and then a straight pipe replacement .

My wife has a 07 320d I got the cat converter box cleaned out and replaced it is not the full effect of a decat yet certainly hold back some soot and fumes, I'm due to take the car for a sowftware upgrade when the budget is better

Just a few things, disconnecting the battery won't reset any adaptions or erase any codes..the ECU is more advanced than that..

An aftermarket down-pipe and a cat converter are not the same, perhaps you meant that the alternative to a decat is a an aftermarket down-pipe? In most modern diesels there normally a catalytic converter or a diesal particulate filter (DPF) very close to the turbo for quick warming and to capture soot..this is replaced with a larger diameter pipe to flow easier and lower EGT early In the system...

Lastly, hollowing out a cat is not the most ideal modification as the empty void that's now created doesn't flow to well, installing a straight pipe inside the cat where the internals used to be could work slightly better and should remain suitably "factory" if a car is still on mp...

:thumbs: