Passing California SMOG TEST on catless midpipe

2sporty · 12-11-2021, 04:12 PM

Since our cars will be due for smog testing soon, are we going to pass smog tests without the secondary catalytic converter that the OEM mid-pipes have? Assume the primary cat is still there.

Obviously, it would fail visual, but I am asking only about the sniffer test.

hellokitty · 12-11-2021, 04:35 PM

CA doesn't use sniffer for new cars. You'll pass the OBD2 smog but fail visual if they see it.

Downeaster1 · 12-15-2021, 05:06 PM

Quote:

Originally Posted by hellokitty

CA doesn't use sniffer for new cars. You'll pass the OBD2 smog but fail visual if they see it.

You won't even pass the OBD portion. You'll either get a CEL for catalytic efficiency, or if you are running a tune that ignores that faulty, your catalyst monitor won't become ready.

2sporty · 12-16-2021, 01:31 AM

Quote:

Originally Posted by Downeaster1

You won't even pass the OBD portion. You'll either get a CEL for catalytic efficiency, or if you are running a tune that ignores that faulty, your catalyst monitor won't become ready.

are you sure this is actually true? The sensor is only on the primary cat, which is on the downpipe.

Can anyone with catless midpipes chime in on this?

2sporty · 12-16-2021, 01:56 AM

I should have consulted this thread instead of having the peanut gallery chime in:

https://f80.bimmerpost.com/forums/sh...1&postcount=10

https://f80.bimmerpost.com/forums/sh....php?t=1625493

hellokitty · 12-16-2021, 04:26 AM

Quote:

Originally Posted by 2sporty

Quote:

Originally Posted by Downeaster1

You won't even pass the OBD portion. You'll either get a CEL for catalytic efficiency, or if you are running a tune that ignores that faulty, your catalyst monitor won't become ready.

are you sure this is actually true? The sensor is only on the primary cat, which is on the downpipe.

Can anyone with catless midpipes chime in on this?

I can confirm this. Like I mentioned in my previous statement, stock cats and aftermarket midpipes with no secondary cats will pass OBD2 readiness but not pass visual.

Downeaster1 · 12-23-2021, 10:30 AM

Quote:

Originally Posted by 2sporty

are you sure this is actually true? The sensor is only on the primary cat, which is on the downpipe.

Can anyone with catless midpipes chime in on this?

OH my bad. I thought we were talking downpipes. Disregard.

ac419 · 03-02-2023, 01:09 PM

Sorry to bring up this old post. Will AA midpipes cause a visual fail? I need to get my car smogged

Sd335i2007 · 03-02-2023, 03:25 PM

Quote:

Originally Posted by ac419

Sorry to bring up this old post. Will AA midpipes cause a visual fail? I need to get my car smogged

Yes, AA mid will fail visual.

ac419 · 03-11-2023, 01:30 PM

Yup, just failed visual, but the BM3 tune relocking worked. They did not detect that it was ever tampered with

2sporty · 03-13-2023, 04:55 PM

correct me if I am wrong, but from what I have heard, a lot of places don't even check the visual for the secondary cats because it's under the middle of the car. You may want to try a different smog shop.

titaniam · 03-21-2023, 04:29 PM

Quote:

Originally Posted by ac419

Yup, just failed visual, but the BM3 tune relocking worked. They did not detect that it was ever tampered with

can you clarify/explain what you mean by relocking? I just flashed mine back to the stock tune, is there anything else that needs to be done beyond selecting the stock tune to flash to? TIA!

12-11-2021, 04:12 PM	#1
2sporty First Lieutenant 244 Rep 356 Posts Drives: bmw Join Date: Jul 2014 Location: Munich iTrader: (0)	Passing California SMOG TEST on catless midpipe Since our cars will be due for smog testing soon, are we going to pass smog tests without the secondary catalytic converter that the OEM mid-pipes have? Assume the primary cat is still there. Obviously, it would fail visual, but I am asking only about the sniffer test.
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12-11-2021, 04:35 PM	#2
hellokitty Brigadier General 2894 Rep 3,726 Posts Drives: '17 M3 ZCP DCT Join Date: Jul 2010 Location: Southern California iTrader: (2)	CA doesn't use sniffer for new cars. You'll pass the OBD2 smog but fail visual if they see it. __________________ 2017 F80 M3 ZCP / AA GESI DPs / Akrapovic Evo / BBS FI-R 19" / Bend Calibration ECUTEK Flex Fuel \| Bilstein B16 DDC + CS EDC / BMC Filters / BMS OCC / CSF HE / ESS CP / Nitto NT555R2 / PD Crank Hub / SPL Suspension / Uniden R7 / Wagner Top Mount IC 2021 Mini GP3 / BMC Filters / BM3 / Cary Jordan E30 / Wagner IC / Remus Race
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12-16-2021, 01:56 AM	#5
2sporty First Lieutenant 244 Rep 356 Posts Drives: bmw Join Date: Jul 2014 Location: Munich iTrader: (0)	I should have consulted this thread instead of having the peanut gallery chime in: https://f80.bimmerpost.com/forums/sh...1&postcount=10 https://f80.bimmerpost.com/forums/sh....php?t=1625493
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03-02-2023, 01:09 PM	#8
ac419 Private First Class 19 Rep 191 Posts Drives: 2015 BMW M3 Join Date: May 2010 Location: So CA iTrader: (5) Garage List 2015 BMW M3 [0.00]	Sorry to bring up this old post. Will AA midpipes cause a visual fail? I need to get my car smogged
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03-11-2023, 01:30 PM	#10
ac419 Private First Class 19 Rep 191 Posts Drives: 2015 BMW M3 Join Date: May 2010 Location: So CA iTrader: (5) Garage List 2015 BMW M3 [0.00]	Yup, just failed visual, but the BM3 tune relocking worked. They did not detect that it was ever tampered with
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03-13-2023, 04:55 PM	#11
2sporty First Lieutenant 244 Rep 356 Posts Drives: bmw Join Date: Jul 2014 Location: Munich iTrader: (0)	correct me if I am wrong, but from what I have heard, a lot of places don't even check the visual for the secondary cats because it's under the middle of the car. You may want to try a different smog shop.
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