Catalytic Converter Removal

[KingSix]

Hello Again Guys,

I am new to the world of BMW's so some of my questions may seem a bit silly to some of you vets out there. I was wondering if it is possible to remove the catalytic converter without disturbing the engine. I am emissions exempt here in NH ( 1992 535i ) so legality is not an issue... I have been told by a few individuals that removing the cat will negatively affect the performance of the engine. Is this true ? Is there a way around it ? A performance chip maybe? I know that was the case with my Dodge Ram.. I removed the cat and used the chip ( A JET Programmable )to reprogram the onboard computer ... any advice would be welcome... Thanks for your time...

[Tiger]

You can go to a local independent shop... no major brand like Midas... They can cut out the cat and put in a generic cat in the place of it... all they have to do is match the capacity and size of cat to original one.

I heard someone had a Magnaflow cat installed for like $120 each. Cat itself is like $70 alone.

If you go to Midas or other major brand co... it will be instantly $600 per side... they do it because they can get away with it.

[KingSix]

Umm yeah.. did I type that question in a different language? I asked if I could remove it without problems... I know I can replace it .. thanks anyway

[bondheli]

rofl

[KingSix]

hmm very helpful forums indeed ....thanks anyway guys

[infinity5]

you won't so much as get your threads read with an attitude like that, just in case you weren't sure. this ain't some honda rice forum. and a great deal of people here don't speak english, so for some it might indeed be a different language.

:)

hmm very helpful forums indeed ....thanks anyway guys

[Dave M]

hmm very helpful forums indeed ....thanks anyway guys

I know english good and can therefore provide the answer you are seeking. Below is my cat-less exhaust. The O2 sensor goes somewhere warm, take your pick.

Stick around and you might learn something,

Good Luck

http://img.photobucket.com/albums/v11/dave_macisaac/Bimmer/Exhaust/Exhaust2.jpg

[KingSix]

you won't so much as get your threads read with an attitude like that, just in case you weren't sure. this ain't some honda rice forum. and a great deal of people here don't speak english, so for some it might indeed be a different language.

:)
OK well you can lose your attitude as well.. I asked I simple question, to which I recieved a reply that was totally off topic, and the next person was kind enough to throw in a "rofl".... hmm wonder why I'd have an attitude ....

[Brett619310]

OK well you can lose your attitude as well.. I asked I simple question, to which I recieved a reply that was totally off topic, and the next person was kind enough to throw in a "rofl".... hmm wonder why I'd have an attitude ....
Possibly you already lost some brownie points from the get-go since you want to remove a cat and kill in the environment, just because you can get away with it legally. If you want some extra horsepower, get an EAT chip and if you need to replace the old cat, go with a high-flow or a magnaflow. The exhaust system is pretty efficient as it is... these aren't Hondas.

[Mobius]

OK well you can lose your attitude as well.. I asked I simple question, to which I recieved a reply that was totally off topic, and the next person was kind enough to throw in a "rofl".... hmm wonder why I'd have an attitude ....Okay. Let's ask a different question.

Why?

Has your cat failed? Do you think this is going to help performance? (Pro tip: it's not - unless you're just dying for that extra 3hp).

A 535i is not OBDII - you don't have any emissions checking apparatus after the cat. You can absolutely remove it - go for it. It's just.. dumb..

[KingSix]

[QUOTE=Mobius]Okay. Let's ask a different question.

Why?

Has your cat failed? Do you think this is going to help performance? (Pro tip: it's not - unless you're just dying for that extra 3hp).

A 535i is not OBDII - you don't have any emissions checking apparatus after the cat. You can absolutely remove it - go for it. It's just.. dumb..[/QUO

OK well, I think I've been flamed enough by the anti-honda guys .. hey I drive a 535, not a 3 series, just for the reason they look too much like hondas, no offense to you guys who drives the newer 3's I just don't like em... In response to your post Mobius, I think its "dumb" ( your words ) to lay down 300+ $$ for a part that I don't need ...No my car hasn't failed, and if you had read the whole thread you would have seen that I am emissions exempt..man you guys are almost as touchy as the guys over @ dtmpower.net

[KingSix]

Possibly you already lost some brownie points from the get-go since you want to remove a cat and kill in the environment, just because you can get away with it legally. If you want some extra horsepower, get an EAT chip and if you need to replace the old cat, go with a high-flow or a magnaflow. The exhaust system is pretty efficient as it is... these aren't Hondas.

hmmm read my original post.... I asked about the chip option... I got a really good response on how to replace the cat....

[Robin-535im]

The O2 sensor goes somewhere warm, take your pick.


Any good shop can weld you a new bung, just tell them where you want it.

:)

I don't know of anybody who has dyno'd with the cat and without since most of us don't "live free" like you NH'ers. We all need our cats. I'd be interested in knowing about gains/losses though if you try it out.

I don't see why you can't do it yourself with parts from Kraagen/Checker/Pepboys (I forget the place of choice back east). They sell straight pipe, cutting tools and bolt up flanges. Sounds like a fun project.

[Brett619310]

hmmm read my original post.... I asked about the chip option... I got a really good response on how to replace the cat....
And the answer is:

chip = good

Here's the link, very helpful and somewhere around 20hp and 20ft/lbs gain for only $200. Also, users report smoother running and better gas mileage, but you have to use 91+ octane.

http://www.bimmer.info/eatchips/

I'm buying one as soon as I get around to verifying my ECU code.

Also, there is a good discussion about upgrades and what is worth doing and not at:

http://www.bmwe34.net

For about the price and trouble of removing the cat, you'll will have a much better car by doing the chip and buying some sport springs. I imagine removing the cat will change the backpressure, so you will probably be better to keep it all stock since that is what the chip assumes. Also, don't get an intake because you may actually loose a few hp from stock.

[Mobius]

In response to your post Mobius, I think its "dumb" ( your words ) to lay down 300+ $$ for a part that I don't need ...No my car hasn't failed, and if you had read the whole thread you would have seen that I am emissions exempt..man you guys are almost as touchy as the guys over @ dtmpower.netHoly ****. We're touchy? Pot? Kettle?

Just because you're exempt doesn't mean you should go and gut your cat - a lot of people think that, and those people are idiots. Why do you want to gut your cat? There's no benefit from it. You do know the catalyst on this car is a $2,000 part, new - right?

If your cat has failed, though - **** it. Weld up some pipe. Just make sure the O2 sensor sees gas from both banks. You're going to have problems if you try to sell the car in a state that requires emissions equipment, though.


In the future; don't be such an ass to people who offer up help that isn't EXACTLY what you were looking for. If you come in here going "hay guys how do I gut my cat" - we're obviously going to be wary of your motive. This is just a car forum on THE INTERNET. Relax.

Regardless, I'm still confused. You don't want to spend $300 on a prt you don't need - and then you say "No my car hasn't failed" - I didn't ask if your car has failed. You said you have no emission inspection. I asked if your CAT has failed. Are you trying to gut your cat for this big 'performance' myth, or are you trying to replace a failed part without spending a lot of money? You never said this, and it's relatively important for the topic at hand. How can we answer your question properly if we don't know what's going on?

[KingSix]

Holy ****. We're touchy? Pot? Kettle?

Just because you're exempt doesn't mean you should go and gut your cat - a lot of people think that, and those people are idiots. Why do you want to gut your cat? There's no benefit from it. You do know the catalyst on this car is a $2,000 part, new - right?

If your cat has failed, though - **** it. Weld up some pipe. Just make sure the O2 sensor sees gas from both banks. You're going to have problems if you try to sell the car in a state that requires emissions equipment, though.


In the future; don't be such an ass to people who offer up help that isn't EXACTLY what you were looking for. If you come in here going "hay guys how do I gut my cat" - we're obviously going to be wary of your motive. This is just a car forum on THE INTERNET. Relax.

Regardless, I'm still confused. You don't want to spend $300 on a prt you don't need - and then you say "No my car hasn't failed" - I didn't ask if your car has failed. You said you have no emission inspection. I asked if your CAT has failed. Are you trying to gut your cat for this big 'performance' myth, or are you trying to replace a failed part without spending a lot of money? You never said this, and it's relatively important for the topic at hand. How can we answer your question properly if we don't know what's going on?



OK its abundantly obvious that you have no freinds or life outside of this forum, "CAR" was a typo for "CAT" I am so very sorry ... Next time I will stop and spell check for you. I have no idea what you are talking about or where you are buying your parts, but your the "IDIOT" (your words) if you spent $2,000.00 for a catalytic converter. I have seen them in places such as Pep Boys for a whole lot less. Lastly, if you go back and read my orginal posting, I was asking for advice on what my options were, noy "hay , how do i gut my cat". In the future please refrain from adding your 2 cents to my posts since you obviously have nothing constructive to add.
Thanks and good luck.. word of advice though... step away from the computer and go outside ...

[Bill R.]

emissions exempt in NH, its still a federal law not a state law, being exempt from testing does not release you from the federal requirement for emissions controls and any shop, and any shop that knowingly removes a cat is subject to a 2500 fine per occurence and any car dealer is subject to a fine of 25000, I would just leave the cat and chip it if you're looking for more performance







Hello Again Guys,

I am new to the world of BMW's so some of my questions may seem a bit silly to some of you vets out there. I was wondering if it is possible to remove the catalytic converter without disturbing the engine. I am emissions exempt here in NH ( 1992 535i ) so legality is not an issue... I have been told by a few individuals that removing the cat will negatively affect the performance of the engine. Is this true ? Is there a way around it ? A performance chip maybe? I know that was the case with my Dodge Ram.. I removed the cat and used the chip ( A JET Programmable )to reprogram the onboard computer ... any advice would be welcome... Thanks for your time...

[KingSix]

emissions exempt in NH, its still a federal law not a state law, being exempt from testing does not release you from the federal requirement for emissions controls and any shop, and any shop that knowingly removes a cat is subject to a 2500 fine per occurence and any car dealer is subject to a fine of 25000, I would just leave the cat and chip it if you're looking for more performance


Well.. I'm not looking for performance so much , as that I am looking for a cheap way out of this.. there is an exhaust leak somewhere in my system, and since I already bought a cat-back system from [URL=http://.bavauto.com (http://bavauto.com), I have , by process of elimination figured out that its that cat that is leaking ... Since I'd rather spand the money on a brakes upgrade, or another item that is actually useful. I refuse to buy a cat when I don't need one.. If prices were more realistic on these items then I would consider it, or if it were legal to used recycled peices I would do that ...Oh well I know what I'mgoing to to now... thanks for your help everybody...

[Jon K]

OK well, I think I've been flamed enough by the anti-honda guys .. hey I drive a 535, not a 3 series, just for the reason they look too much like hondas, no offense to you guys who drives the newer 3's I just don't like em... In response to your post Mobius, I think its "dumb" ( your words ) to lay down 300+ $$ for a part that I don't need ...No my car hasn't failed, and if you had read the whole thread you would have seen that I am emissions exempt..man you guys are almost as touchy as the guys over @ dtmpower.net

He wasn't asking if you passed or failed emissions, he was asking if your catalytic converter itself has failed. If the unit has failed, the biscuits become loose and float around the shell. This is annoying because it sounds like pellets loose in the cats when you drive. So, that was what was implied by "did it fail". Also, a failed cat will not flow as well, you will notice significant power loss.

Now, this isn't DTM Power, we don't talk about "kill stories" or bodykit molding... but, if you're interested, keep an eye on this forum until later today. I will be posting information of my custom exhaust i just got on involving two magnaflow hi-flow cats and an M5 B&B Triflo exhaust.


PS: Go to bmaautoparts.com, look up your car model on the online catalog. OEM catalytic converter for 92 525i has a dealer price of $1,200. FYI.

[Mobius]

"CAR" was a typo for "CAT" I am so very sorryI only asked because it caused confusion. In one case you car has failed inspection, in another your cat is falling apart. I was asking if you actually meant that - not flaming you for a typo. Please calm down.


I have no idea what you are talking about or where you are buying your parts, but your the "IDIOT" (your words) if you spent $2,000.00 for a catalytic converter.Holy ****, absolutely you're an idiot to spend $2k on a cat. I merely mentioned that because it might make you more reluctant to smash up the innards of your cat if it's working fine.

(And John K - I just said $2k because it's like $1,900 in the realoem ETK. Okay, $1,200 - still expensive. :) )

[JonE]

You can go to a local independent shop... no major brand like Midas... They can cut out the cat and put in a generic cat in the place of it... all they have to do is match the capacity and size of cat to original one.

I heard someone had a Magnaflow cat installed for like $120 each. Cat itself is like $70 alone.

If you go to Midas or other major brand co... it will be instantly $600 per side... they do it because they can get away with it.
Soooo, there was a hole in it after all!
Kinda funny how Tiger's first answer was probably the right one all along! Still, kinda fun watching people flinging bombs back and forth...