[Route 16]

My idea is to keep the OEM primary cat shells but replacing the filters with high flow/performance cats. Is there one in the market that promotes the performance and sound aspect of being catless while still passing smog *sniff* test, regardless if inspection will be done by OBD plug in.

***Oh why don't you just buy catless headers/make better collectors.

Because I'm going the cheap route/OEM look/not trying to reach "300 HP" t(".)t

[Taskmaster]

But will it really be cheaper?
You could just buy some headers and swap them when you need to - or you can buy 2 highflow catalyst and have to pay someone to weld them in....

Or just buy AFE/Euro headers (the Euro headers probably wouldn't gain much over OEM)

[JDane07]

I haven't seen any, ever, but sniffer tests are pretty much obsolete nowadays. CA doesn't require them, do they?

[Route 16]

Originally Posted by TheAxiom

But will it really be cheaper?
You could just buy some headers and swap them when you need to - or you can buy 2 highflow catalyst and have to pay someone to weld them in....

Or just buy AFE/Euro headers (the Euro headers probably wouldn't gain much over OEM)

$200-400 i'd imagine per cat. Haggling with install/uninstall with different headers is a waste of my time imo. I'd rather go for one long lasting solution. Putting high flow cats would be optional. I wouldnt think smog guy would look for an oem stamp then the other thing is if it passes the sniffer test (performance/sound is up to debate on research from other forums)

[Route 16]

Originally Posted by JDane07

I haven't seen any, ever, but sniffer tests are pretty much obsolete nowadays. CA doesn't require them, do they?

Thats the thing, i really havent seen/heard shops using obd to pass. Get your smog done Dane, you're slacking hahah.

[Taskmaster]

Originally Posted by Route 16

$200-400 i'd imagine per cat. Haggling with install/uninstall with different headers is a waste of my time imo. I'd rather go for one long lasting solution. Putting high flow cats would be optional. I wouldnt think smog guy would look for an oem stamp then the other thing is if it passes the sniffer test (performance/sound is up to debate on research from other forums)

$400 per cat means that the AFE for about $1000 is a good deal.

[Route 16]

Originally Posted by TheAxiom

$400 per cat means that the AFE for about $1000 is a good deal.

Budvlad's thread is a dead end, I'm trying to find a link for the AFE headers. If it is worth it to me, I'll look at the pricing and do proper steps for the review (dyno/smog check, whatever).

[Nordkeyz73]

I was tempted by the Supersprint headers, and St|g swears by them. But because where I live does a visual inspection AND the OBDII test, I'm also looking at afe headers.

[SlickE90]

I just did my smog a few weeks back and he used the obd to pass.

[Route 16]

Originally Posted by SlickE90

I just did my smog a few weeks back and he used the obd to pass.

Opened the hood too? I havent seen norcal smogs do obd yet.

[Route 16]

Originally Posted by Nordkeyz73

I was tempted by the Supersprint headers, and St|g swears by them. But because where I live does a visual inspection AND the OBDII test, I'm also looking at afe headers.

If i can only find the afe header link i'd look into it for consideration.

[SlickE90]

Originally Posted by Route 16

Opened the hood too? I havent seen norcal smogs do obd yet.

Not that I remember.

[Taskmaster]

Originally Posted by Route 16

If i can only find the afe header link i'd look into it for consideration.

They are sold all over the place?

[andrey_gta]

AFE seem to be the best option for you - high flow and pass visual


Euro exhaust n52 manifolds ( 2005-2007) have a huge catalic converter even though their flange is sexy equal distance design.

The n53 manifold with the sexy flange have a smaller catalic, but I dont know if theirs matches all the connections on an n52 and may need a custom job to close one spot on the n53 design

[Love The Drive]

Here's a link to the AFE headers.

http://afepower.com/shop/details_new...ily&brandID=99

[jc5988]

Originally Posted by Route 16

My idea is to keep the OEM primary cat shells but replacing the filters with high flow/performance cats. Is there one in the market that promotes the performance and sound aspect of being catless while still passing smog *sniff* test, regardless if inspection will be done by OBD plug in.

***Oh why don't you just buy catless headers/make better collectors.

Because I'm going the cheap route/OEM look/not trying to reach "300 HP" t(".)t

if you have N51, u can try switch to N52 exhaust manifold, it has less dense cell.

other option will be get some 200cell metal cat and pay machine shop cut and weld the manifold. please let us know how it goes if you ever done such thing. CA is a B*tch comes to smog test.

http://www.mil-spec.org/200-cell-cats/

[Route 16]

Originally Posted by Love The Drive

Here's a link to the AFE headers.

http://afepower.com/shop/details_new...ily&brandID=99

Oh ok, I wasn't sure if it was that one. I only focused on seeing E82 chassis but that's a grip of money still. I can't go with this option.

[Route 16]

Originally Posted by jc5988

if you have N51, u can try switch to N52 exhaust manifold, it has less dense cell.

other option will be get some 200cell metal cat and pay machine shop cut and weld the manifold. please let us know how it goes if you ever done such thing. CA is a B*tch comes to smog test.

http://www.mil-spec.org/200-cell-cats/

I have n52 but this is more of my style but I'm just wondering if a BMW stamp matters *80% of my mind says it doesn't matter*
I will be asking a local performance shop and show them that link. That helps a bunch!

[TheSt|G]

Originally Posted by Nordkeyz73

I was tempted by the Supersprint headers, and St|g swears by them. But because where I live does a visual inspection AND the OBDII test, I'm also looking at afe headers.

That's rough. Would it be possible to point to your secondaries and say "Here they are!"?

[jc5988]

Originally Posted by Route 16

I have n52 but this is more of my style but I'm just wondering if a BMW stamp matters *80% of my mind says it doesn't matter*
I will be asking a local performance shop and show them that link. That helps a bunch!

as long as the welding look OEM, i will say smog test wont bother to check the stamp. its kinda hard to check those too, but first thing u see from engine bay is the welding and shape of the manifold, so those are easy to tell.

[Route 16]

Originally Posted by jc5988

as long as the welding look OEM, i will say smog test wont bother to check the stamp. its kinda hard to check those too, but first thing u see from engine bay is the welding and shape of the manifold, so those are easy to tell.

I wouldn't mind if iPE did start doing our headers or the whole catless system if we can get close to the sound of an F1 type iPE like the m3's, with valve control.

[chris82]

Originally Posted by jc5988

if you have N51, u can try switch to N52 exhaust manifold, it has less dense cell.

other option will be get some 200cell metal cat and pay machine shop cut and weld the manifold. please let us know how it goes if you ever done such thing. CA is a B*tch comes to smog test.

http://www.mil-spec.org/200-cell-cats/

Can you provide proof on the N52 having a less dense cell than the N51 in the main cats?