[SeanS54]

Is it true that the 2nd cats aren't strong enough to clean emissions so therefore running catless downpipes with stock exhaust will destroy the 2nd cats?

I hate the smell of catless so I was thinking of running downpipes with the stock 2nd cats.

Can you guys chime in? How many miles on the car w/ catless downpipes and stock 2nd cats?

[tscdennab]

One thing I noticed is that after the demoval of the primary cats, the smell becomes very strong even with secondary cats in place, which means that the primary cats are the ones that do most of the emissions cleaning. So it doesn't matter if you run secondary cats or not, it will stink anyway. I am going to take them off very soon.

[Forcefed3]

I have catless downpipes and I have never smelled anything.

[chili36]

Never noticed a smell either.

[ianthegreat]

Same, never noticed any smell whatsoever.

[Forcefed3]

I am about to delete secondary cats, I dont mind the smell. I dont think there will be much of one anyway.

[FedeM]

I've original exhaust and catless downpipes with no-probs.

Initially, just upgraded (for the first 100-200miles), i've felt a little like-toast/popcorn-smell... But I think it's normal when u put on a new exhaust...

[marv85]

Originally Posted by gbreeE90

I have catless downpipes and I have never smelled anything.

good to know! I'm installing my catless DPs soon

[SeanS54]

how many miles do you guys have with catless downpipes and stock 2nd cats?

[topspin]

I have AR catless DPs with stock secondary cats and exhaust.

I only noticed a slightly stronger exhaust smell compared to stock. The difference is not very noticeable at all.

I have about 10,000 miles on the car since I installed the catless DPs.

[bmwturbopower]

I just installed some UR catless DP's and the first 20-30 miles smelled because of the PB blaster I used to get some bolts off. If there is a smell it is very minute.