DE CAT??

stevie G

///Member
Hi guys,

just had a new throttle butterfly and a new fuel pump fitted at tune tech (thanks for the advice on where to go) now im sending it back on monday for air filter,engine oil, gearbox oil and filter, diff oil and coolant system flush
and to sort out my oil leaks and some cosmetics (fender liners & rubber under windscreen) so now that I've spent 20k trying to get this car perfect
I was wondering about DE CAT...

firstly have any of you done this and caused any ecu problems/warning lights etc. the guy at powerflow is saying he hasn't had any issues with BMW decats that he has done

secondly which is a better deal 1. full decat (just take out all the catylists and leave the original pipe on) R1800.00

2. fit a new pipe from the headers back (some call this branches) R2750.00

all your thoughts would be greatly appreciated.:=):
 

msm

Well-known member
stevie G said:
firstly have any of you done this and caused any ecu problems/warning lights etc. the guy at powerflow is saying he hasn't had any issues with BMW decats that he has done

Just make sure your O2 sensors are plugged into the right banks again after the decat, and it should be fine. Powerflow guys got them mixed up on mine, but I managed to get it sorted out.
 

Bayn46

Active member
msm, your threads scared me away from doing a de-cat :rollsmile: but I'll probably go for it when I'm on leave again. Powerflow is just across the road from where I work which is cool.
 

msm

Well-known member
Bayn46 said:
msm, your threads scared me away from doing a de-cat :rollsmile: but I'll probably go for it when I'm on leave again. Powerflow is just across the road from where I work which is cool.

There's lot of guys who decatted their E46's - Don't stress - you should be fine. The gains are worth it :thumbs:
 

moranor@axis

///Member
Official Advertiser
the best thing to do is get a set of 328i or 323i catless branches like msm did... there is no point in after market branches unless you are doing a full free flow...

cats must die... every time i drive behind a newer car up a hill all i smell is cats...
 

stevie G

///Member
moranor said:
the best thing to do is get a set of 328i or 323i catless branches like msm did... there is no point in after market branches unless you are doing a full free flow...

cats must die... every time i drive behind a newer car up a hill all i smell is cats...

the R2750 option is aftermarket branches and the rest of the pipe, i assume this is a "freeflow"

the R1800 option is to de cat my branches and pipe

the question is, which is better? I'm thinking that if i do the full aftermarket branches and pipe, I will still have the original pipe with the cats in place and maybe if i need to, i will be able to bring it back to standard...

is this possible or will the original stuff be destroyed in the process?
 

moranor@axis

///Member
Official Advertiser
R2750 is a bit cheap for a freeflow and branch... im guessing its just some resonators where the cats used to be and a branch...

try find some 328i or 323i catless branches they go for about 600... get them to make a 'downpipe' to connect them to your stock exhaust and fit resonators where the secondary cats used to be...

a good freeflow with branches should be 4k-6K if they doing it for R2750 i think it will just make noise...
 

stevie G

///Member
moranor said:
R2750 is a bit cheap for a freeflow and branch... im guessing its just some resonators where the cats used to be and a branch...

try find some 328i or 323i catless branches they go for about 600... get them to make a 'downpipe' to connect them to your stock exhaust and fit resonators where the secondary cats used to be...

a good freeflow with branches should be 4k-6K if they doing it for R2750 i think it will just make noise...

do you think Powerflow can do the full free flow with branches or maybe you know of the best place to go to for this? or do i buy the freeflow and branches first and them get them fitted or do they usually get made/fabricated for each car seperately?

i wonder what exactly they are talking about doing for the R2750 job...
 

Yulz9081

Honorary ///Member
R2750 could just be branches incl fitment. That is the price of Viper/TNT/Wildcat branches from Powerflow.
Like the guys said above, just see if you can source the 328 catless headers (scrapyard maybe) and put resonators where the cats used to be and and and as msm said make sure the sensors go back in the right place! I had endless trouble because of that. You may need a cat fooler where the rear sensor plugs in, speak to the okes at Powerflow.
To optimize this mod once complete, chip it or do software, then it will make a vast difference and consumption should even drop.
 

moranor@axis

///Member
Official Advertiser
clearance it tight so the exhaust has to be made on the car... hopefully some joburg guys can put you onto a good exhaust shop...
 

XMAX

///Member
stevie G said:
fit a new pipe from the headers back (some call this branches) R2750.00


According to my interpretation of the above statement... The current Headers (Branches) will remain in place, and only the pipes, including resonators, will be replaced from front to back.

Absolutely no offence, but Stevie G seems to be under the understanding that installing new pipes after the headers are called the branches.

According to what I know, the Headers ARE the branches. the pipes only would be regarded as the freeflow part. you commonly hear people say that theyve got a "Branch and Freeflow". They say it like that because the Branches are usually a different component of the Exhaust System.



I hope that this helped and didnt add more confusion to the case.

IMHO, if Powerflow quoted you R2750 for a Freeflow only, not including branches, (which according to my interpretation is what they did), then R2750 may not be a bad price.
 

moranor@axis

///Member
Official Advertiser
R2750 makes sense for a free flow only...

now that the picture might be completely different...

do you have cats in your branches?
you can feel them when the car is cold on the left side of your engine...
you will have ether:
25.png

30.png

24.png


if you dont have cats in the branches its a very cheap and easy job :rollsmile:
 

stevie G

///Member
I do know that branches and headers are the same thing :=):

but i was thinking that they were telling me R2750 for branches/headers and a pipe all the way back from there... sorry for the confusion

thanks for that diagram, i will have a look in the morning, however the guy at powerflow told me over the phone that i will have cats in the branches as standard... thats why im thinking I should just get the whole thing branches and freeflow together because i would like to keep the standard stuff one side

im also gonna go talk to steves auto clinic guys at lunch time today...

thanks again for all the info/opinions i appreciate it :thumbs:
 

moranor@axis

///Member
Official Advertiser
exhaust is kind of big how will you get it home? if you go free flow you should also get the car chipped, if you dona want to chip then its better just to decat and not have a noisy car...
 

stevie G

///Member
moranor said:
exhaust is kind of big how will you get it home? if you go free flow you should also get the car chipped, if you dona want to chip then its better just to decat and not have a noisy car...

I will have to pick up the exhaust in the hilux...

but ja true what you're saying i was thinking DASTEK because we know the dudes there, but ja i dont want to do it half way so either the full job with the chip and some sort of induction/K&N filter or something and keep the original pipe or im gonna leave it standard and save up a bit more money, this car is costing me plenty already...
 

Sankekur

///Member
Don't waste your money on a performance filter as they do nothing, but hasten the demise of engine components.
 
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