[Der]

Hi all,

I do not drive an e90, but a z4 e89 35is, however I though that I would be able to find more info on this forum, especially given the same N54 engine. My question is regarding secondary cats. I love my stock exhaust, but would like a bit more deeper sound. I belive on our cars, deleting the secondary cats can help it. My only worry is smell. Can anyone chime in on whether the car will develop a bad smell or not?

Thanks!

[einbruch10]

No smell. Wont make to much of an increase in sound, but im not sure of the difference between our exhaust and the z4.

[Der]

Originally Posted by einbruch10

No smell. Wont make to much of an increase in sound, but im not sure of the difference between our exhaust and the z4.

Thanks! I know that the sound increases by 7-10% on average and becomes deeper. I was just worried about the smell. For some reason some people suggest the car will smell, while some disagree. But some many people are running catless dp's,so surely a simple secondary delete will be fine...

[Mike@N54Tuning.com]

Better bet getting catless downpipes if you want a sound increase.

Mike

[Fred_Boosted]

If you go fully catless, it will smell for sure. But if you still have stock down pipe, smell should be fine.

[Der]

Thanks guys. I cant go for downpipes due to warranty and various other reasons. So secondaries it is

[Snypa]

It may rasp some.

[einbruch10]

do what everyone does for the PE mod on the e90, get two 1792 vibrant resonators to replace your secondary cats. its what i did before downpipes and worked great for me.

[Jnat]

I have secondaries hollowed and Tig'd back in, kept factory kitties and sound is better then stock. Common sense says it has to reduce back pressure to some degree so slight performance increase let's say and my 02's still work as designed. I like it!

[Der]

Thanks guys