Catless x-pipe stinks badly :(

[werly]

I have been running a catless & resonator-less xpipe for about a month.

First and the biggest issue that I have is the smell/emission.

Prior to installation I understand the smell will be prominent but how it is right now is beyond my tolerance level. I can live with some smells as long as it is not as bad like now. Also the carbon coming out from the rear is turning my exhaust tips yellow; I am afraid it is just a matter of time for the rear bumper becomes the same color so I am thinking about adding a set of 200 cpi cat at stock secondary location. I was told to add a set of 400 cpi cat. Which one should I go for?

Another issue is the sound, I am satisfy with the sound while cruising after the xpipe installed, but cold starting the car in my neighborhood becomes my fear. I have yet to receive any verbal complain but the car after the xpipe never fails to receive looks from them when I drive by and I am sure those looks are barely friendly...

To solve cold start issue I thought about deleting my secondary air pump to restrain the airflow, but since I am adding a set of cat it should be wise to keep the air pump for cats to work properly?

If only I can find a solution that reduces the smell completely while only kills the cold start noise but still retaining the sound while driving. But I know there is trade offs.

As for now I am leaning more towards adding a set of 200 cpi cats and see how it goes for smell and cold start sound. Any advice is welcomed

[Krozi]

Don't mess with the secondary. Just get the 200cell cats like you said, and maybe look into a tune to turn off the CEL and get rid of the cold start.

[tibra1]

Im sorry but what did you expect?,..any catless setup is going to have a bad smell..its all about if you are willing to tolerate it

And on this platform makes absolutely no sense..have been catless before myself..mostly on turbo applications where the power gains are substantial..not on my M3..not worth it imo

[werly]

Originally Posted by Krozi

Don't mess with the secondary. Just get the 200cell cats like you said, and maybe look into a tune to turn off the CEL and get rid of the cold start.

By saying don't mess with the secondary do you mean don't put 200 cell cat there but at the primary location instead?

I thought about getting a tune because I know it kills the cold start cycle and also reduces the smell a bit, but I doubt the smell will improve much by just a tune.

[Krozi]

Originally Posted by werly

By saying don't mess with the secondary do you mean don't put 200 cell cat there but at the primary location instead?

I thought about getting a tune because I know it kills the cold start cycle and also reduces the smell a bit, but I doubt the smell will improve much by just a tune.

I mean secondary air pump

It took me a bit to get used to the smell also...but after a while it didn't bother me much. Just throw some 200cell cats in there and you'll like it!

[aus]

200-300cpi cats should be ok. I'm thinking of adding another set of 100cpi cats to my Akra X-pipe because it still smells.

[Grail05]

I recommmend running 200 cel cat and a resonator...

200 cat is not bad to be honest i can barely smell mine... only on start up but barely... and if you decide to put one on make it like the AKRA set up...

now a no cat xpipe it gives me a headache... so

[werly]

The smell is actually just a bit over my limit, but the carbon coming out from the pipe really gets on my nerve. I want to get it fixed before my rear bumper turn yellow

[Rekrul]

Eh.. its really not bad. I feel like there are a lot of sensitive boys on this forum. The power is substantial.

[Grail05]

Originally Posted by Rekrul

Eh.. its really not bad. I feel like there are a lot of sensitive boys on this forum. The power is substantial.

really? ... it smells so bad sensitive i donw know... ... yea power is there but the torque really sucks so bad at low RPM... cant wait to put my 200 cel cat on and a resonator...

[aus]

Originally Posted by Sean05

really? ... it smells so bad sensitive i donw know... ... yea power is there but the torque really sucks so bad at low RPM... cant wait to put my 200 cel cat on and a resonator...

Agreed. Maybe I'm just old but I hate driving behind a ricer car and smelling the car.

.

[Rekrul]

Originally Posted by Sean05

really? ... it smells so bad sensitive i donw know... ... yea power is there but the torque really sucks so bad at low RPM... cant wait to put my 200 cel cat on and a resonator...

Eh.. I dont sit behind my car so I dont care lol. I always loved smelling the cars at the track.. I like the smell when I start it up in the garage. As for the torque.. I don't think the loss is there and if it is its not substantial. I do know that my car is more apt to spin its tires though from 2500+ on. MY brother noted the same thing after driving it. Keep in mind, I have DCT too. So I can control my power band a bit better than say a 6spd. I am never under 2000 rpms.

[L4ces]

Originally Posted by Rekrul

Eh.. I dont sit behind my car so I dont care lol. I always loved smelling the cars at the track.. I like the smell when I start it up in the garage. As for the torque.. I don't think the loss is there and if it is its not substantial. I do know that my car is more apt to spin its tires though from 2500+ on. MY brother noted the same thing after driving it. Keep in mind, I have DCT too. So I can control my power band a bit better than say a 6spd. I am never under 2000 rpms.

It is a price to pay when going catless. I tried it too. But it was only after I drove behind mine did I begin to feel effd up. With that said, I'd do it again if HFCs killed the smell. My car ran extremely rich which may not be the difference. Also, my rear bumper and truck gathered soot and little yellow spots. That may not happen to all, I dunno.

[Grail05]

Originally Posted by aus

Agreed. Maybe I'm just old but I hate driving behind a ricer car and smelling the car.

.

im with you bro... it smells so bad im about to take the xpipe off... but ill wait a couple weeks...

yea maybe im old as well...

[Grail05]

Originally Posted by SehrSchnell

Tiny yellow spots have nothing to do with being catless.

care to share...

being catless gets your bumper turn into yello well spots of yellow "carbon" anyways... then it turns dark yellow if you dont clean it up...

[tibra1]

Either way over time some kind of discoloring will occur..cost of doing business...thats why catless setups on turbos are better..its a cleaner exhaust emission than an NA..even still it would also discolor the bumper over time

[L4ces]

Perhaps more frequent waxing and extra coats of wax will prevent discoloration. It will probably slow down the process. That is what I started doing when I had the xpipes on. Just stating the obvious.

[Rekrul]

I was my car regularly. No spots or deposition. I also don't drive like a bat out of hell everywhere. 18.4 MPG mixed driving.

[1MOREMOD]

just stand in your garage with it running. you will learn to love the smell.

[Rekrul]

Originally Posted by chriszeh

just stand in your garage with it running. you will learn to love the smell.

Amen.

[joshparzi]

this explains why my trunk is yellow

[///M Ryder]

The smell is part of the experience......learn to live with it...............Phil