Decat - The way to go!!

[andrewbuch]

Rather leave it until plans finished. Then get it done.

 

[Epoc]

+1 ... mine is going out soon in about 800km then Kwik-Fit here I come. :clap:

@Olorin .. I have spoken with a stealer mech manager and he reckons decatting will void warranty FYI.

 

[Olorin]

Epoc, thank you for letting me know ! I guess it's no decat for me then. :bawling: Damn. Just about everything I want done, including chipping the car and a remap is out of the question. Oh well, I'll have to wait 2 more years...

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So Jiggy, what kind of difference did the decat make to your car ? Details and impressions please.

 

[Sankekur]

These is a way to remove the cats without voiding your motorplan, just have someone remove the internals of the cats, this will give the same effect as a decat, but it will still look like the cats are inplace, this will of course only work on cats that don't need cat foolers.

 

[Olorin]

Cat foolers ?

 

[XMAX]

Decatting sounds like a good idea but I wonder how aftermarket motor plans would react to decatting. Would be interesting to phone and check.

 

[Ashman]

I have a stock 316i. have been toying with the idea of modding it. this sounds very tempting.

 

[Jiggy]

At first, you notice a slight tone change, not louder but raspier, with the rev's climbing much easier from idle.

Only after the first few days you start to feel the difference, i recon the motor needs to get used to expelling the air faster so like any new thing to the car, it needs to be run in... Plus the resonator needs to burn through inside...

But now im happy i did it, not only does the car pull much better but the fuel ecomony had gone up drastically!!

For those who are going to do it, try this: feel the cat once its removed, after an hour (thats roughly how long it takes) the cat is still so hot that you cannot touch it with a bare hand. Now i seriously doubt that can do any good on a 13 year old car...

My advise: REMOVE THE CAT!!!

 

[peanuts]

Ok guys, i have a E46 330i and would like to Decat...
however, i do not want the sound of the car to change at all as i think it is perfect currently...

do i just get the cats removed and put straight pipes or a resonator?

 

[P1000]

Ok guys, i have a E46 330i and would like to Decat...
however, i do not want the sound of the car to change at all as i think it is perfect currently...

do i just get the cats removed and put straight pipes or a resonator?

Best would be to have them remove the insides of the cat. Though the sound will still change, but less than straight pipes.

 

[Leon]

Hi
Sorry for being stupid:hammerhead:
I have a E36 318IS 1997 model with almost 200 000km on
Is it worth the +-R700-00 to remove the cat?
Does it really improve fuel consumption and performance to justify the price?:dunno:

 

[Jiggy]

@ Peanuts - they replace the cat with a box so the sound will hardly change..
@ Leon - remove the cat, it will only do your car justice :thumbsup:

 

[Olorin]

The real question is, would removing the cat do the 320i justice. Everyone tells me what a friggin slow car I've got and that chipping it and changing exhaust wouldn't make much of a difference. If you still think removing the cat will make a nice improvement in acceleration or added torque then I'll try and find a way to get around BMW. Or contact them and find out. But based on what I've learned from guys around here, it's not worth the hassle but I guess everyone's expectations are different.

 

[andrewbuch]

The real question is, would removing the cat do the 320i justice. Everyone tells me what a friggin slow car I've got and that chipping it and changing exhaust wouldn't make much of a difference. If you still think removing the cat will make a nice improvement in acceleration or added torque then I'll try and find a way to get around BMW. Or contact them and find out. But based on what I've learned from guys around here, it's not worth the hassle but I guess everyone's expectations are different.

The older the car is, the more blocked the cat will be therefore the better results you get from removing it.

If the car is still new (5 years & under 100K Km) then I would say leave it in for now..

 

[Olorin]

Also, sorry to be such a noob, but can someone more knowledgeable please explain what happens when the cat is removed ? How does it improve performance and improve fuel consumption ?

 

[andrewbuch]

the cat gets old & blocked, so exhaust gasses have to force their way out..

no cat means exhaust gasses have an easier time getting out

 

[Olorin]

Well my car is 2005 so it's not new. So then I suppose the improvement would be pretty big. Then I can finally race against 325's. Finally. Just kidding.

 

[andrewbuch]

My car is a 2000 Model, with 143000Km & I am thinking of removing it.. But fuel consumption is not bad, & dont get that rotten egg smell much.. So the cat is still fine I think

 

[nicwes]

I have a 2003 320i with 190 000km on the clock. Fuel consumption is not too bad, but with my driving style I can use better economy..

Can anyone recommend a good place to go to. I am in Auckland Park, but I don't mind driving somewhere where i know they'll do a good job.

 

[msm]

Ok guys, i have a E46 330i and would like to Decat...
however, i do not want the sound of the car to change at all as i think it is perfect currently...

do i just get the cats removed and put straight pipes or a resonator?

The 330i has cats in the header too, which are quite restrictive. If you want to see decent gains, you need to remove these as well, or replace with a catless header.