Catalytic converter

[E36M3]

I see a lot of people with e36's that remove their catalytic converters......are there a lot of problems associated with doing this, and how will it sound if i do it with my stock exhaust? and is it easy to do?

 

[wood_e]

When you remove a cat converter you are comitting an illegal act. They are required by US law for on-road use. There probably won't be any problems if you remove it, unless your state runs emissions testing. Your car better be tuned up really well if you are trying to pass one of those without a cat converter.

The sound on your stock exhaust will probably not change. If anything you'll get a little rasp.

It probably wouldn't be easy to do yourself, unless you had a lift. Good luck trying to get an exhaust shop to chop it off...

 

[epj3]

It would be super easy to do himself, bmw's exhausts are bolt on. All you need is a "test" or "Straight" pipe.

 

[wood_e]

Ahh.......... wow I wish ford was that smart

 

[jms325]

the easiest way to do it is to take the cats off and just smash the shit out of the guts. then it will look like you have cats too if you have to sell the car to someone who's not as lucky as us and has to get their car inspected.(clearly this is a little shady) I was going to do this until I heard someone say they lost some power because of loss of back pressure. If you have alot of miles on your car it might have the opposite effect though.

 

[manuel]

you can remove it. what some people do is add an 02 similator(i think thats the name) else your gonna have a CEL. of course ive only seen it done or turbo aplications. passing the smog test might be harder.

 

[E36M3]

oh ok well we dont have emissions tests here in sc and the car has 100 000 miles on it

 

[FnlApprch]

E36M3 - a shop will not remove your cats because they will get fined. Have you looked into a high flow cat, or Supersprint center resonator?

 

[E36M3]

a friend of mine owns a shop and he would do it for me, thats not the problem the only thing i was wondering about was weather i will have any problems with it

 

[FnlApprch]

Oh, I don't know if you have to worry about the O2 sensor, on my car it actually comes before the cat.

 

[carcus]

It was a common mod on the F-Body to delete the cat and replace it with a straight pipe. Not really any gains unless you have new heads, a cam, and a full exhaust. On the F-Body, you will throw a check engine light without O2 sims. There is no benefit for doing it to a BMW. Funny thing, I just saw on another BMW website, some guys wanting to install an exhaust cutout on their BMW. They saw it on a muscle car site and said.....that is cool, wonder how I can do that to the E36......LOL. If you have a buddy that wants to do it for free, its up to you. Not much of a HP gain if any with a stock car. If you ask an exhaust shop, the EPA will fine the crap out of them. The only time they will R2 a cat is if it is damaged or needs to be replaced. I believe in some states they have to report the replacement. Just my 2 cents.

 

[FnlApprch]

For me, I already have the headers, and a Borla cat-back. There are two, 2" pipes that come off of your exhuast manifold. It then flows into one, 2" pipe and then back into two seperate 2" cats. I plan to install a 3" Magnaflow cat. I will eliminate the choke point of the single 2" pipe and will be able to install a bun for the 02 sensor as not to throw the CEL. Theoretically it should give more power, and the total operation is less than $250. The shop say if I don't like it it will be about $30 to change it back.

 

[carcus]

For me, I already have the headers, and a Borla cat-back. There are two, 2" pipes that come off of your exhuast manifold. It then flows into one, 2" pipe and then back into two seperate 2" cats. I plan to install a 3" Magnaflow cat. I will eliminate the choke point of the single 2" pipe and will be able to install a bun for the 02 sensor as not to throw the CEL. Theoretically it should give more power, and the total operation is less than $250. The shop say if I don't like it it will be about $30 to change it back.

Its your money, do what makes you happy. With stock heads and cam, not going to see anything. Just my 2 cents.