Is 034 High-Flow Cat capable of passing California smog?

[Spike00513]

[dalazybastard]

No.


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[walky_talky20]

It does not have a CARB (California Air Resources Board) number, so it should immediately fail visual inspection. Visual inspection will check for either the OEM equipment in place or a CARB number on an aftermarket unit. Some have gotten it to pass by making it visually identical to the stock unit by welding the OEM heat shields from the stock cat onto it. Not saying you should do that, just saying some people have done that.

As far as the actual emissions part of it - it does have higher emissions than a stock cat (even a high miles one), but many people have gotten it to pass. It's just on the upper end of the scale. Doesn't pass with flying colors - and certain variables can put it over the top. But it it is a cat and it ought to be able to reduce emissions to acceptable levels to pass a sniffer in most cases.

My advice would be - do your homework on what they are going to check and make sure you are prepared for that. Then have a backup plan (like, swapping in the stock cat) if it doesn't work out.

[Spike00513]

I thought exhaust gas measuring probes are only used on older cars?
And that on OBDII cars, a smog testing station simply does a visual inspection and plug into the OBDII port, to make sure there is no check engine light on and that the car has fully set readiness on all monitors, reading that the car is OK and everything works fine.

In other words,
OBDII scan tool: Hello car? Is everything OK?
Car: Yes.
OBDII scan tool: Ok. Thank you.

In which case, IF this is true, I wonder if the car has a threshold or tolerable range, that actual values have to fall within.
For example, if an HFC would be slightly worse/inefficient, but not severely enough to trigger a CEL.

Unless a spacer is used? I hear J-shaped ones work well.
I'm not sure how they actually work. If it reads higher oxygen content by being farther away from the cat's exhaust emission stream, spaced with a little buffer cushion of oxygen. But wouldn't airflow passing by (exhaust) simply create a vacuum and suck that pocket of oxygen out?

[Chuckster]

2000 and newer models don’t require tailpipe testing and just get plugged in. There is still a visual inspection, which this part will fail. OBDII is checking for poorly functioning emissions equipment, so typically anything that raises those values like HFC’s or catless will trigger a MIL. To work around that, people try to use those sensor spacers, which will fail a visual inspection too, so it gets tricky to mess with the oem equipment at all.

[walky_talky20]

I guess I'm old. As of 2010, that's correct - Cali does OBD2 check only for 2000+ cars.

There is definitely a tolerable range. So the factory cat has room to age a bit without throwing codes. But as far as how far that range goes - these aftermarket cats are usually right on the edge and won't reliably keep the codes away without some help (like a spacer or what have you). There are a lot of variables, so it can't be said for certain whether the specific cat you get from 034 will be able to keep the light off on your specific car. So there is that hurdle as well as the visual issue.

[seanf86]

I'm 6 years in on 034 HFC and no CEL for catalyst efficiency and no 02 spacer. We have no emission testing here but it would pass obd2 I would assume as I've got no CEL.

[frogspit]

From what I’ve read the 034 hfc won’t cause a MIL and may even set your monitor as ready but it will fail when the tech visually inspects. If it doesn’t have the CARB logo or number or something it will not pass.

I have a CARB certified magnaflow cat that I swap in for emissions, then swap back to my test pipe after


I think I’ve read something about them switching to a system that can check for forced readiness too, so it’s best just to get an OEM or CARB certified cat in there for inspection


I think the real question is will they care about a FMIC

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[BARRY]

from my research the 034 high flow cat which I believe is a magnaflow 200 cell will barely not pass. this is if your engine is in tip top shape and cat is still performing well.

but...in California it wouldn't qualify as approved for usage as a certified replacement.

[agentsmith988]

I've ran an 034 HFC for years and I pass on all readiness checks. However, I do get a secondary O2 sensor code for being out of threshold once in a great while (most of the time it's just a soft code that doesn't throw a MIL).

In Utah I just passed a few days ago with the soft O2 sensor code stored on the ECU with no MIL (all readiness checks showed green). I'm glad I don't have to deal with CARB...

Bonus: The guys at the inspection station liked my car so they gave me a free carwash. Wooooo!

[MetalMan]

On my old '98.5 A4, the 034 HFC didn't pass the sniffer with a F21.
On my 2001.5 A4, the same 034 HFC would trigger cat codes without a spacer.

So everyone may have different experiences.

[MagnaFlow]

It does not have a CARB (California Air Resources Board) number, so it should immediately fail visual inspection. Visual inspection will check for either the OEM equipment in place or a CARB number on an aftermarket unit. Some have gotten it to pass by making it visually identical to the stock unit by welding the OEM heat shields from the stock cat onto it. Not saying you should do that, just saying some people have done that.

As far as the actual emissions part of it - it does have higher emissions than a stock cat (even a high miles one), but many people have gotten it to pass. It's just on the upper end of the scale. Doesn't pass with flying colors - and certain variables can put it over the top. But it it is a cat and it ought to be able to reduce emissions to acceptable levels to pass a sniffer in most cases.

My advice would be - do your homework on what they are going to check and make sure you are prepared for that. Then have a backup plan (like, swapping in the stock cat) if it doesn't work out.

All good info!

[BARRY]

https://ssl.arb.ca.gov/AftermarketParts/catalysts

APPROVED aftermarket Catalytic Converters. buy a universal and throw on the appropriate flange you need. 3 inch would be ok. V-Band probably will not pass as it probably would be considered easily removable.

Test Group Name Application Type Part Manufacturer Manufacturer
Part Number Cert Level Executive Order Vehicle Class Total Converters Catalyst Location Catalyst
Part Type
3ADXV01.8342 ALL AP Emissions Technologies, LLC 760024 LEV1 ULEV D-754-1 PC 1 Underbody UNIVERSAL
3ADXV01.8342 ALL AP Emissions Technologies, LLC 764186 LEV1 ULEV D-754-1 PC 1 Underbody DIRECT FIT
3ADXV01.8342 ALL Airtek, Inc. 760024 LEV1 ULEV D-280-105 PC 1 Underbody UNIVERSAL
3ADXV01.8342 ALL Airtek, Inc. 764186 LEV1 ULEV D-280-105 PC 1 Underbody DIRECT FIT
3ADXV01.8342 ALL Airtek, Inc. 760024 LEV1 ULEV D-798-6 PC 1 Underbody UNIVERSAL
3ADXV01.8342 ALL Airtek, Inc. 764186 LEV1 ULEV D-798-6 PC 1 Underbody DIRECT FIT
3ADXV01.8342 ALL Car Sound Exhaust System, Inc. 456034 LEV1 ULEV D-193-114 PC 1 Underbody UNIVERSAL
3ADXV01.8342 ALL Car Sound Exhaust System, Inc. 456035 LEV1 ULEV D-193-114 PC 1 Underbody UNIVERSAL
3ADXV01.8342 ALL Car Sound Exhaust System, Inc. 456062 LEV1 ULEV D-193-114 PC 1 Underbody DIRECT FIT
3ADXV01.8342 ALL Miller CAT Corporation 310005 LEV1 ULEV D-709-5 PC 1 Front of the vehicle UNIVERSAL
3ADXV01.8342 ALL Miller CAT Corporation 310100 LEV1 ULEV D-709-5 PC 1 Front of the vehicle DIRECT FIT
3ADXV01.8342 ALL Valina, Inc. 207022 LEV1 ULEV D-562-75 PC 1 Underbody UNIVERSAL
3ADXV01.8342 ALL Valina, Inc. 207030 LEV1 ULEV D-562-75 PC 1 Underbody UNIVERSAL
3ADXV01.8342 ALL Walker Manufacturing Company 82667 LEV1 ULEV D-182-57 PC 1 Underbody DIRECT FIT
3ADXV01.8342 ALL Walker Manufacturing Company 82667 LEV1 ULEV D-182-59 PC 1 Underbody DIRECT FIT

[19jdog]

Im in Cali. Ive been running JHM downpipes with HFC's for the last 3 years. I pass smog everytime.

[Spike00513]

Im in Cali. Ive been running JHM downpipes with HFC's for the last 3 years. I pass smog everytime.

Well that's 3.0, with JHM parts.
IDK how their cat material compares to the 1.8T 034 unit.
I wonder how the JHM DP's are passing visual in CA...

[19jdog]

Well that's 3.0, with JHM parts.
IDK how their cat material compares to the 1.8T 034 unit.
I wonder how the JHM DP's are passing visual in CA...

I had my exhaust guy tuck my cats high up. When the smog tech gets on his hands and knees with a flash light to check I get supper nervous. I'm just stating that having HFC is illegal but if done right can pass the visual and sniff test. Maybe I'm getting lucky!

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[pablolizarraga]

I had my exhaust guy tuck my cats high up. When the smog tech gets on his hands and knees with a flash light to check I get supper nervous. I'm just stating that having HFC is illegal but if done right can pass the visual and sniff test. Maybe I'm getting lucky!

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Interesting. Ive never had my smog guy go underneath or do sniffer test.

Is your car louder or does it emit an exhaust smell that makes them suspect youve got HFC’s? Starting to look into these as I just got a 0431 intermittent pop up; but all readiness monitors are still green. Would love to go HFC’s as my understanding is you get increase in power. Is that correct as well?


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[Spike00513]

I had my exhaust guy tuck my cats high up. When the smog tech gets on his hands and knees with a flash light to check I get supper nervous. I'm just stating that having HFC is illegal but if done right can pass the visual and sniff test. Maybe I'm getting lucky!

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I don't get it. So you took straight-pipe JHM DP's, and had an exhaust guy install cats on them? Why not just buy the JHM HFC ones, with cats already in them? Would they not be a similar price?

Also, I assume non-dealership shops get into smogging to make money, as with anything else, such as repairs, alignments, etc.
The rules might say that it has to be done visually with eyes on target, meaning no mirrors
but if they can't afford a lift or something (which also adds time), maybe they just walk around it using a mirror.
In which case, it's kinda hard to see cats (on a 3.0L at least) from above or below, with the big engine squeezed in a small space, and then downpipes having to curve around a big heavy transmission.

Whereas on a 1.8T, the cat is much easier to see. There's only one, and it's right there visible between the airbox and engine.

[19jdog]

Whoa, I bought jhm downpipes with HFCs. Spent over a 1000 bucks in 2014. I'm just giving my 2 cents on my experience. Who in the hell goes to the dealership for a smog?

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[DarkoNova]

I had my exhaust guy tuck my cats high up. When the smog tech gets on his hands and knees with a flash light to check I get supper nervous. I'm just stating that having HFC is illegal but if done right can pass the visual and sniff test. Maybe I'm getting lucky!

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Good to know the jhm pipes still pass smog.

Was that with the sniffer?

[audireme]

In Cali, 2004 car would not be inspected a sniff test.

[DarkoNova]

Yeah, my smog guy said 2000 and newer cars don't get the sniff test. I'm just scared that I'll go to get it smogged and they'll look under the car or put the thing in the tailpipe and then I'm screwed.

I'd rather have some kind of cat, even if it doesn't have an EO number, than no cat at all...

[2004a4b630QT]

I agree. I got the catless dp's because I've got almost 2 full years before inspection again, but I have no intention of trying to get through inspection without HFCs. I'll weld them in and take out the "neck down" to stock ends when I get a 2.5inch catback.

[MetalMan]

Yeah, my smog guy said 2000 and newer cars don't get the sniff test. I'm just scared that I'll go to get it smogged and they'll look under the car or put the thing in the tailpipe and then I'm screwed.

I'd rather have some kind of cat, even if it doesn't have an EO number, than no cat at all...

They won't stick the sniffer in there, because your car is a 2000+ model year and they don't waste time with the sniffer.

Cat without EO is nearly as bad as no cat... unless you "know a guy".