Removing Catylitic Converter.

[AlaskaBlue]

I want to replace my exhaust from the header back with one continuos pipe straight to the muffler. What do I need to do to get rid of the Catylitic converter. Do I need an Oxygen Sensor simulator? If so where can I get one? If you have any suggetions for how to set up the system or interesting places for it to exit tell me please.

[gooten1]

You need a saw. I had mine cut out when I put on my supersprint. Went through a bunch of sawzall blades...apparently that pipe is really tough. I don't have an o2 sensor simulator...I just ignore the check engine light. (Probably a bad idea....) I suppose you could cover the sensor so no dirty exhaust hits it...that might fool it. Or just make the light come on again, I'm not sure.

[AlaskaBlue]

Do you tell any difference power wise without the cat?

[mischief]

yes by removing the cat your free up the engine by removing the backpressure coused by the cat
you gain very few hp at high RPM and loss HP at low RPM.
and on some vehicles you loos power or dont see anything
and depending on the set up of the exhoust your car might sound like a weedwacker on steroids.
i have removed the cat on my 95 TI didnt see much gain
now im looking at hiflow cats i hate the weedwacker sound and its to loud i cant talk on my cell even when im at sitting at a red light

by removiing the cat
car sounds like ****,attracts cops,neighbors hate you for waking damn up at the middle of the might,car wount pass emissions and dont forget the fine of $4000 or more for not having a cat,and the ECU receives wrong signal from the oxygen sensor cousing engine to run lean and in time will damage your engine

dont be stupid or at least buy a HIFLOW CAT
http://www.machv.com/busrachigcat.html
http://www.drgas.com/Street-Catalog.asp
http://www.jegs.com/cgi-bin/ncommerce3/CategoryDisplay?cgmenbr=361&cgrfnbr=631
http://www.car-sound.com/catalog/universal/500.aspx
http://www.randomtechnology.com/products.html

[AlaskaBlue]

I live in Indiana 1/2 of the cars here have cats removed, and I know you can buy a simulator somewhere to make the car run right, but I don't know where. As for a fine I have never heard of anyone getting one here. I am sure the law exists it just isn't enforced. And there would probally be some kind of rebelion if Indiana had an emissions test. Our cars never even have to go through a saftey inspection after they are bought new. As for noise the neighbors won't mind noise because they all have V-8s of some sort with straight pipes.

[mischief]

i live in va in the dc area
lucky you you dont have emissions
what year is the Ti
if its a obd-1 the sensor is in front so this wount effect the car after removing the cat.
obd-2 has a sensor on the front of the cat and a senser behind the cat called heated oxygen sensor dont they sell simulators for hondas and i dont think they make simulators for m42/m44 engines try and splice the wires

[hsvbama318ti]

You don't need to buy a high flow cat. That is bull**** and nothing but a marketing gimmick. All you need if you want to get rid of the rasp is a racing resonator and not some supersprint racing resonator at that. I have dealt with cars for a long time and not just bmws, and people out there just want to sell you something "specifically for your BMW", bull****! I have no catalytic converter with 2 1/2" piping all the way back to a 10" racing resonator which is universal and a straight through magnaflow system. It sounds great, no pissed off weedeater sound. A fine mellow sounding yet decently loud exhaust. Sure you could spend $800 dollars on "bmw specific exhaust components" if you want an $800 dollar sound because they did all this for you.

[gooten1]

yes by removing the cat your free up the engine by removing the backpressure coused by the cat
you gain very few hp at high RPM and loss HP at low RPM.
and on some vehicles you loos power or dont see anything
and depending on the set up of the exhoust your car might sound like a weedwacker on steroids.
i have removed the cat on my 95 TI didnt see much gain
now im looking at hiflow cats i hate the weedwacker sound and its to loud i cant talk on my cell even when im at sitting at a red light

by removiing the cat
car sounds like ****,attracts cops,neighbors hate you for waking damn up at the middle of the might,car wount pass emissions and dont forget the fine of $4000 or more for not having a cat,and the ECU receives wrong signal from the oxygen sensor cousing engine to run lean and in time will damage your engine

dont be stupid or at least buy a HIFLOW CAT

With our cars, you have to have it at high RpMs if you want any kind of performance anyway, so the low rpm loss is negligable. What you didn't read is that I removed the cat after I put on a Supersprint exhaust. Which means there is still muffling going on, so very little of your "weedwhacker" sound. It's not loud at all...but does sound off as the throttle is opened. However, it isn't so loud that it interferes with conversation. On the other hand, I had been running straight pipes from the cat back...which was terrifically loud and horribly raspy and awful. I wouldn't reccomend it unless you wanna sound like a V-8 at idle and a turbocharged leaf blower at speed.

It isn't the oxygen sensor that gets the reading, it's the catalytic converter sensor that is behind the cat that's reading the fault. The o2 sensor is further up the system, if I'm not mistaken.

I have noticed a gain after removing the cat, as I drove the car after putting on the exhaust but before removing any other parts. I wasn't thrilled with the performance...so I removed the cat which improved the sound and increased performance. I can feel the difference (butt dyno), but don't have any numbers to prove it.

Mischief, what kind of set up are you running that makes the car so loud? Straight pipes? A coffee can muffler? Glass pack? Something along those lines? Just wondering.