e39 525d problems after catalitic converter cut out

[velo96]

hi so i own a bmw e39 525d 2002 and recently i noticed that there was a lack off power so i thought it may be the catalitic converter was blocked so i cut the exhaust completely off before the cat and i started the car it seemed fine then i went to drive it and there was loads of white smoke and a smell like the turbo was gone and the throttle was sticking for a few seconds and making really bad tapping sound from engine. is this normal when the cat is cut out, something to do with the return pressure? i was looking everywhere online and i couldnt find a topic like that so i posted my own.

[323i E30]

hi so i own a bmw e39 525d 2002 and recently i noticed that there was a lack off power so i thought it may be the catalitic converter was blocked so i cut the exhaust completely off before the cat and i started the car it seemed fine then i went to drive it and there was loads of white smoke and a smell like the turbo was gone and the throttle was sticking for a few seconds and making really bad tapping sound from engine. is this normal when the cat is cut out, something to do with the return pressure? i was looking everywhere online and i couldnt find a topic like that so i posted my own.

Have you considered getting the computer scanned for stored codes before cutting parts from your car..?
It might not have to do with your exhaust at all, and you are definitely missing some sensors now that advise the dme about the air/fuel ratio.

[Breeze1]

Hello and welcome to the forum velo96,

I don't want to sound dramatic but if I were you I'd go look for help elsewhere, because there is a "you're on your own if you don't do exactly as the gourous say, blow a lot of smoke up your car's a** and bow down before them" policy on this forum (I genuinely hope they prove me wrong, for your own sake).

More seriously, and based on what I just did (https://www.bimmerforums.com/forum/s...5#post30189535), I'd say it depends on how you proceed but also on sheer "luck", as some cars go through that process without major issues and some don't. It depends on how many and what sensors you deleted or damaged, if you flashed the DME or not (some don't need it to run properly, some don't run properly even with the appropriate software and procedure done if for e.g. a sensor get damaged in the process, see my post about that).

You could look on the web for a post describing the procedure done by someone successfully and see what steps you have missed.

hi so i own a bmw e39 525d 2002 and recently i noticed that there was a lack off power so i thought it may be the catalitic converter was blocked so i cut the exhaust completely off before the cat and i started the car it seemed fine then i went to drive it and there was loads of white smoke and a smell like the turbo was gone and the throttle was sticking for a few seconds and making really bad tapping sound from engine. is this normal when the cat is cut out, something to do with the return pressure? i was looking everywhere online and i couldnt find a topic like that so i posted my own.

[velo96]

Have you considered getting the computer scanned for stored codes before cutting parts from your car..?
It might not have to do with your exhaust at all, and you are definitely missing some sensors now that advise the dme about the air/fuel ratio.

yes i had a computer plugged in before i cut the cat and there was no stored codes, so next weekend im gonna try and weld the exhaust back together before it messes the engine up.

[shadowpuck]

Hello and welcome to the forum velo96,

I don't want to sound dramatic but if I were you I'd go look for help elsewhere, because there is a "you're on your own if you don't do exactly as the gourous say, blow a lot of smoke up your car's a** and bow down before them" policy on this forum (I genuinely hope they prove me wrong, for your own sake).

More seriously, and based on what I just did (https://www.bimmerforums.com/forum/s...5#post30189535), I'd say it depends on how you proceed but also on sheer "luck", as some cars go through that process without major issues and some don't. It depends on how many and what sensors you deleted or damaged, if you flashed the DME or not (some don't need it to run properly, some don't run properly even with the appropriate software and procedure done if for e.g. a sensor get damaged in the process, see my post about that).

You could look on the web for a post describing the procedure done by someone successfully and see what steps you have missed.

lol....wow.

that's MR. guru to you.....

[Breeze1]

lol....wow.

that's MR. guru to you.....

Right... I thought "guru" was cocky enough...Guess I was wrong...

[shadowpuck]

Right... I thought "guru" was cocky enough...Guess I was wrong...

haha....nice!