Catalytic converter gone bad...time for exhaust :)

The time has come...my cats have gone bad in the car and I have been waiting to do an exhaust setup for my 2000 328i e46 4dr.

I probably should replace the cats, but I am eager to hear what other setup possibilities are out there for this type of car.

Other BIGGER issues at the time are these codes:

P1188 and P1189 ... fuel control problems
P0300 | P0302 and P0303 ... cylinder misfires

P1250
0173
0170
0150
... not sure exactly what to do first, but need to get her back on the road!

Any help is greatly appreciated fellas!

I'm partng out 2 cats I have or 250 they are yours....no codes works perfectly only 78k on them

Sent from my SPH-D700 using Bimmer App

Second I have my stock front Mani if you want it. But if you don't have emission laws do headers you will fall in love.

Sent from my PantechP9060 using Bimmer App

Tanner is right....if you have no mandatory DMV emissions inspection, you`re free to go for headers....you`ll see a performance gain, and a nice sound as well. Good luck !

Ok, so I am going to take out my worn cat converter and do a header back system. Does anyone have a quick write up on how I go about this?! Can I get a header and bolt it up to my stock exhaust? Any suggestions on how I go about this would be awesome!

Originally Posted by ragethreadsusa

Ok, so I am going to take out my worn cat converter and do a header back system. Does anyone have a quick write up on how I go about this?! Can I get a header and bolt it up to my stock exhaust? Any suggestions on how I go about this would be awesome!

Sure, you can do it....any decent muffler shop can weld/fab up any interconnecting pipes you may need. A less-restrictive, free-flow exhaust would give you another 5 to 10 HP, but if you need to save $, the stock setup will suffice for now.

My catalytic converter seems to be faulty and my service engine light soon comes on and goes off from time to time. I am really not willing to buy a new catalytic converter for my 2002 525i, with 175K miles. Can someone please let me know of an alternative as I really don't like that light coming on while driving?

Originally Posted by PCD

My catalytic converter seems to be faulty and my service engine light soon comes on and goes off from time to time. I am really not willing to buy a new catalytic converter for my 2002 525i, with 175K miles. Can someone please let me know of an alternative as I really don't like that light coming on while driving?

If your converters are bad they need to be removed or replaced your catalyst is most likely clogged if your "cats are going bad." This will get worse and start hurting the cars performance. There is no easy fix to them. As for the light you can get a defouler kit that removes the O2s from the exhaust flow.

Sent from my PantechP9060 using Bimmer App

since ur gonna get a cats delete, i would go all the way and install cat-less headers (if ur state permits it)
i'm looking to get the headers in the near future from bimmerbrakes.com for around 200$
for any info, our good friend SPDSTKR will help u out, he's got them installed and very pleased with them

Cats don't "go bad". There is a problem within the combustion cycle (lean or rich) or there is contamination within the converter (coolant from a head gasket, or oil from rings).

Figure out what's wrong before you do anything. Those codes will lead you to what caused the failed cats, not a result of.

Jon

Cats do go bad or clogged ^^^
U will lose power

Originally Posted by heztheone

since ur gonna get a cats delete, i would go all the way and install cat-less headers (if ur state permits it)
i'm looking to get the headers in the near future from bimmerbrakes.com for around 200$
for any info, our good friend SPDSTKR will help u out, he's got them installed and very pleased with them

You rang?

Yes... if your state has no emissions regulations, then I suggest installing headers. See... your catalytic converters are built into the headers; they're not in-line like most other vehicles.

What I would do if I were you would be the following:

1) BimmerBrakes.com headers. Their website is currently undergoing some changes, but e-mail them at info@bimmerbrakes.com for a quote on their product. Make sure you tell him SPDSKTR sent you!

2) When you get the headers installed, go to an exhaust shop and tell them you want a single 3" exhaust. You pick and choose your choice of mufflers and resonators.

3) While picking parts for the exhaust, you can also choose to put a race-grade catalytic converter in-line with your exhaust and relocate your O2 sensors so you stay legal and don't have a smelly car.

Headers DO make a difference in performance. My good friend smolck installed mine for me and followed me to the exhaust shop to get them connected to the rest of my exhaust (I had my headers coated by Jet-Hot and they apparently warped at the outlet due to the extremely high temperatures they were exposed to, so a custom piece was required). On the drive to the exhaust shop, I was seriously running open headers. It was loud. Stupid loud. Not fun loud.

Once they hooked up the pipes, though...



I have an odd popping noise at idle (my guess is uneven exhaust gas pulses), but once it gets up to 3,500 RPM and above, it sounds absolutely mean. The other benefit is the power. I actually chirped the tires going into third gear once (with 18" wheels and smolck in the passenger's seat). I also piss off smolck's 3.46 equipped ZHP, which is really something considering I have the stock 2.93 differential.

TL;DR: Headers are a great choice if planning to "replace your cats." Install a race cat in your new exhaust system to stay compliant with emissions laws (if applicable). Go with a 3" single pipe exhaust from the headers back for maximum power gains.

The full combination will probably net you around 9 to 12 WHP.

Good luck.

EDIT: Just for fun...





Through all this, though, my car is not in the greatest shape, it's loud, it's smelly, and it's not as refined as a ZHP. It's still a friggin' blast to drive.