e46 - catalytic converter

[[email protected]]

Hi,

I've read a few threads of people de-catting their BMW's. My question is, how do you know you need to decat?

 

[P1000]

Hi,

I've read a few threads of people de-catting their BMW's. My question is, how do you know you need to decat?

They are designed for 160000km, so after that its a good idea to remove them. Also if you ever used leaded petrol, they would probably be destroyed now, and just acting as a plug in the exhaust.

 

[Spy007]

Cats must DIE................

---

PS also they wiegh a ton so you gain just from loosing the weight. .....

 

[Iceman007]

OK so who has decat there BMW's on this forum?
Give us your results

 

[[email protected]]

so 180000km might be a good time to rip it out? I read somewhere else (might have been this forum) that you need to do something with your airflow sensor too after decatting. this true?

 

[Epoc]

@vincelang ...

Check these links out ... some members have posted their responses and explanations.

http://www.bmwfanatics.co.za/showthread.php?tid=12211

http://www.bmwfanatics.co.za/showthread.php?tid=7231

http://www.bmwfanatics.co.za/showthread.php?tid=9295

http://www.bmwfanatics.co.za/showthread.php?tid=7773

 

[Iceman007]

Ok Powerflow ask me R1800 to remove cats and Steves Auto Clinic asks R1450. now thats expensive. Where else can I go. The thing is at powerflow the guy opens up the Exhaust Cats and removes the inside and then closes them up neatly which I prefer. where as Steves they just cut them out and insert straight pipes in there place. Any opinions or sugestions?

 

[P1000]

Noiseboys or TnT

 

[Matt Q]

Remove pipe and replace with straight pipe.. simple

 

[ChrisBrand]

Bud, Powerflow quoted me R600 to have the cats removed and straight pipes fitted. I also replaced the centre box in the exhaust system for better sound and that was an additional R700. All that much cheaper than R1800.

 

[andrewbuch]

Seems like they quoted to remove the centre cat & the cats in the headers

 

[Iceman007]

Yes was at Power flow in Belville and they were very helpfull and yes they remove the 2 CATS in the Headers and the 2 in the exhaust. They Cut them open neatly and remove the inners and then they close them up neatly and looks origanal again like the Cats are there, but they are not. The Only way you going to know is by the sound they say. It tends to sound like an M3(tiny):thinking:. Im also lucky my model 325 e46 only has 2 sensors and they are before the cats, so I dont need foolers.

So when I have a chance I think Ill spend the day there while they do it and post some Pictures. What do you guys think and are there any opinions?:wave:

 

[Truvalu]

I very, very nearly removed the cats off my car yesterday, but I got in underneath the car on the lift and the owner of the fitment centre looked at it as well and said "these things still look brand new, it would be a waste to remove them" nothing loose, no rattles etc.

I still want to do it though....

175000km on the clock now

 

[andrewbuch]

Yes was at Power flow in Belville and they were very helpfull and yes they remove the 2 CATS in the Headers and the 2 in the exhaust. They Cut them open neatly and remove the inners and then they close them up neatly and looks origanal again like the Cats are there, but they are not. The Only way you going to know is by the sound they say. It tends to sound like an M3(tiny):thinking:. Im also lucky my model 325 e46 only has 2 sensors and they are before the cats, so I dont need foolers.

So when I have a chance I think Ill spend the day there while they do it and post some Pictures. What do you guys think and are there any opinions?:wave:

So the guy that tunes all other guys about leaving their cars stock & saying if you want a faster car buy a faster car.. Now he wants to Decat...

Dude make up your mind, please

 

[Iceman007]

Yes was at Power flow in Belville and they were very helpfull and yes they remove the 2 CATS in the Headers and the 2 in the exhaust. They Cut them open neatly and remove the inners and then they close them up neatly and looks origanal again like the Cats are there, but they are not. The Only way you going to know is by the sound they say. It tends to sound like an M3(tiny):thinking:. Im also lucky my model 325 e46 only has 2 sensors and they are before the cats, so I dont need foolers.

So when I have a chance I think Ill spend the day there while they do it and post some Pictures. What do you guys think and are there any opinions?:wave:

So the guy that tunes all other guys about leaving their cars stock & saying if you want a faster car buy a faster car.. Now he wants to Decat...

Dude make up your mind, please

Ai Ai :banghead: Its no for performance but to prevent future blockage. U dont even notice the differince. Preventative Maintenance.

 

[ChrisBrand]

Yes was at Power flow in Belville and they were very helpfull and yes they remove the 2 CATS in the Headers and the 2 in the exhaust. They Cut them open neatly and remove the inners and then they close them up neatly and looks origanal again like the Cats are there, but they are not. The Only way you going to know is by the sound they say. It tends to sound like an M3(tiny):thinking:. Im also lucky my model 325 e46 only has 2 sensors and they are before the cats, so I dont need foolers.

So when I have a chance I think Ill spend the day there while they do it and post some Pictures. What do you guys think and are there any opinions?:wave:

So the guy that tunes all other guys about leaving their cars stock & saying if you want a faster car buy a faster car.. Now he wants to Decat...

Dude make up your mind, please

Ai Ai :banghead: Its no for performance but to prevent future blockage. U dont even notice the differince. Preventative Maintenance.

Hahaha. my advice, that cat can looking shiney as a piece of silverware from the outside but you don't know how that thing looks on the inside. Proposition, take the cat off, if its full of "stuff" ditch it, if its not that bad still ditch it

 

[Truvalu]

Final question... Should I go for resonators or straight pipe?

I noticed that the two pipes coming from the manifolds are different sizes, anyone else noticed that? E39 1997 528i 176000km

 

[Iceman007]

Ok Finally removed 2 of my 4cats(the 2 under the car) at Power flow for R500 and the car sounds better when you floor it, and the revs pick up easier. Ill monitor fuel consumtion and see how it is over a time period

 

[maduna]

Ok Finally removed 2 of my 4cats(the 2 under the car) at Power flow for R500 and the car sounds better when you floor it, and the revs pick up easier. Ill monitor fuel consumtion and see how it is over a time period

So far how was your findings with regards to the decat procedure.....
Thanks in advance for your feedback...lolraise:

 

[GPGrobler]

Ok Powerflow ask me R1800 to remove cats and Steves Auto Clinic asks R1450. now thats expensive. Where else can I go. The thing is at powerflow the guy opens up the Exhaust Cats and removes the inside and then closes them up neatly which I prefer. where as Steves they just cut them out and insert straight pipes in there place. Any opinions or sugestions?

If they put just straight pipes in or hollow out the cats, the car is going to sound horrible, you need a T-pipe or a X-pipe and resonators fitted when putting in straight pipes in place of the cats.

Other members may correct me, but just hollowing them out will adversely affect performance.