Hold on a second,
There could be a bit of confusion here on my behalf.

I'm from the uk we test CO. When my car was put through its MOT ministry of Transport Test my emissions on a standard exhaust were 0.00 % ( zero) and 49ppm HC.
The 2nd O2 sensor can be turned off if it come on with a performance flash if you have it set to do so.
So what are we saying.
That a 100 cell cat will not remove co at all or not enough to show a difference between the pre and post cat . Which is what is being measured.

Are your emission tests looking at the o2 sensors or are they a real time co measurement with a sniffer up the exhaust??

 

Exactly and you dont get those on a $2K exhaust system.. yet many a new here are used to paying that... bottom line, you get what you pay for...

 

I knew you were going to say that.... lol
they dont have anything to do with CO measurement... its when a 100 cell cat fails it throws a CEL... most 100 cell cats do it within a short period of time... I say 2 years just a guess.. but we can leave the post 02s off and keep the car in "ready mode" so the computer they hook up does not see it is as " not ready".

Bottom line, use a stock one , spend a day in the garage.... call it a day.. otherwise dont expect miracles unless you pay for one...
I started to put mine on every two years, stock that is, before I went for the test... then got home and swapped out again..

 

Ah...

Do you know what sort of CO levels a good 100 cell will let throught.
For eg, I think my standard exhaust has 300 Cell cats?? ( mind you there are 4 of them)
They removed all the CO. The reading was zero. Here in the uk I think the fail limit is 0.3% ( please chip in with the exact figure if you know it. My figure 0f 0.3% pass limit is something I thought I heard the tester mumble when I asked him as he tested my car )

 

I have no idea.... that is up to the individual companies that make them...

 

I wish our emission test was a light and OBD2 test.

 

Well I didn't intend to make your day less sunny, Sunny. I don't have "documentation" per say, it's just well known that "hi-flow" cats do not function on any level near OE cats and most car enthusiast communities consider them worthless. I've seen worse emmisions readings using a 300 cell cat than a straight pipe. The issue on that vehicle was the cat wasn't getting up to operating temp to function at all and was creating a restriction. If you live in an area that only does OBD2 testing for '96+ vehicles, then you will be ok with a tune that simply turns off the O2 sensor code. Generally on a 911, they have no idea where to look for a cat for the visual. If they inquire if you modified the exhaust because it's loud, say no or you had the muffler replaced. The only areas who still sniffer test OBD2 vehicles are generally commie areas such as Chicago. You will most likely fail a sniffer test with anything but the OE cats. If you pass, you got lucky, the operator is a moron, or your vehicle has a tune which is optimized for emissions and sacrifices everything else. No doubt very lean and very advanced timing with high EGTs. Have an EGT gauge? Wideband?

JH

 

A tune definitely drives the airflow and power. What else would raising the boost via a tune do?

JH

 

So ARD your 100 cell cats go through cali smog? If so then they will go
through Jersey smog. I never heard of doin a flash to get through smog.
Marski can you provide same quality cats. With no flash. that nuts to do a flash. I want a exhaust only that works. Not some almost working exhaust. No offense but that is the way it is. ARD can you provide the model of your europipe. Is it the quiet version?

 

Ard do you have the quiet version? It looks like all the aftermarket stuff available will not pass smog in Jersey. Its silly to remove a exhaust every year just to get through smog inspection. I would rather pay more for something that works without any issues. I'm not building a race car but on that has better sound then stock and with some performance gain.
thanks for all honest responses on this issue.

 

I do use German metal matrix 100 cell cats... but how can I extend a guarantee if companies that produce them do not as they know very well that 100 cell cats are not street legal...

You might as well get 300 cell cats with a nice 3" thru X design and be done with it...
Many tuners disconnect the post 02s for cel bypass etc... you just dont know about it... Euro and US... I say the majority does.... especially if your getting a 100 cell cat exhaust.... and most say it out right that it is not intended( the exhaust with 100 cell) for street legal road use.
Bottom line is: you want performance you need low cell count.... you want to pass whatever emission testing then you better know what it takes to pass and don't get in a mess and pay later...
this is what I make...



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Technically there is no aftermarket exhaust that will pass California smog. Technically. Unless the exhaust has been listed (ie "Carb Certified") by CA, it doesn't matter how clean it tests. I am a bit of a broken record about this, but new folks need to know.

I pass a sniffer, cats nice and hot (not excessive, but 45 minutes of freeway driving). No codes either, no special "turn off the secondary O2 sensor" programs... (note that a flash can turn off the program that looks for Cat Efficiency codes- which is done by comparing the signal from the pre-cat o2 sensor to the post-cat o2 sensor. If the program is turned off, it doesn't matter WHAT the cats are doing (they could be missing) but you will get a 'secondary o2 not ready' code. Since all smog programs allow one or two 'not ready' codes when you do smog, if everything else is OK, you will pass.) Confusing? Sorry..

Interestingly, I was going to buy a quiet when a Loud popped up on ebay- I jumped on it and am SO glads I did. I'd have regretted the quiet.... just me.

A

PS Sounds testy here, not sure why- I know two of the vendors here are honest and pretty straight talkers...maybe paying the price for market confusion that has built up?

 

Marski - Ard thanks for your up front advise.
Marski you here me correctly. I dont want to pay twice. What i want is to get some sound that is not going to blow me out of the car or drone "sound like a porsche". This car is way to quiet. So you offer 300 cell system? This is now a option and i guess with 3 inch pipe i get some free flow. I'm keeping my engine stock and has more then enough power for the few DE events i do.
I just want to pass nj smog and dont want to flip exhaust systems. I go crazy enough with flipen track pads...lol
thanks again for your honest help..

 

Yes I do offer 300 cell cats...

 

SunnySide.. When i went through inspecton here in nj in october. They plug into the "junction box" under driver side dash. then take readings.
They use to snif using a wand. that is the best i can describe. So if you use 100 cel and get a flash. From the cars point of view - your fine.
But when u go every two years here in NJ they plug in and take a reading.
So that is why i want a exhaust that will get me through smog. I had a 100 cell on my 964 and just passed but the readings for that car are not as strict as for my 2002 turbo. The 964 sounds great - not loud - the turbo is slient.