How to pass emissions with catless downpipes

[horsepower_and_hounds]

I will be trying this soon i think. I have catless set up and running the BM3 stg 2 tune and have 2 not ready..... we are allowed one. I have all sensors installed as OEM and have turned off the pre-cat heating modes in the tune so I still have these and need one of them to go away. Still trying to figure out an easy solution sio I dont have to pull the pipes out come emissions time.

[Tamtino]

Does anyone have any experience with bm3 and can help me get my f82 pass deq followed the guide but had some trouble and it been a PITA
Can pay for your time ty

[rsmrk3]

Current exhaust setup - VRSF Catless DPs + VRSF Mid-pipe + MPE V2 Muffler.
Followed instructions from OP, not too bad of a job considering the time and effort it would take to swap DPs.

I failed the first time because of a bad O2 sensor, once i replaced it- Everything worked and passed.

(Note: I recommend getting a different set of spacers as fail-safe before installation just in case if spacers recommended by OP don't fit the O2 sensor)


Back to BM3 Stage 2 with some corn juice!

[depaulhifi]

Originally Posted by Info@mad-us.com

Just gotta purchase the correct parts. Still a way cheaper alternative plus most states don't have any type of testing at all so a tune will take care of the annoying light.

Strict testing states are tough so best to just follow the laws.

I think a key takeaway should be to simply spend the extra $50-100 in parts and 2 minutes in labor upfront when installing catless downpipes so you don't have to worry about it when it comes time to renew your sticker.

I'm having my factory DPs reinstalled and flashing back to stock next week. A couple weeks later I'll be back to have my Eisenmann catless DPs put back on, this time with mini cats installed in the O2 bungs so I don't have to worry about it next time.

[Azurite_F80]

Maybe I missed it.. but is there any harm in leaving the mini cats (bigdaddiesgarage ones) installed permanently? For context, thinking of the "casual" BM3 93oct tunes, stock turbo etc.

[jaylazy2020]

Has anyone in Europe go thru this?

MOT inspection in Uk for example.

Thanks

[rsmrk3]

Originally Posted by Azurite_F80

Maybe I missed it.. but is there any harm in leaving the mini cats (bigdaddiesgarage ones) installed permanently? For context, thinking of the "casual" BM3 93oct tunes, stock turbo etc.

I reached out to 'bootmod3' regarding this and they said- having the O2 spacers (Minicats in your case) will affect the fuel trims.

[Azurite_F80]

Originally Posted by rsmrk3

I reached out to 'bootmod3' regarding this and they said- having the O2 spacers (Minicats in your case) will affect the fuel trims.

Great to know, thank you!

[Azurite_F80]

To unclip the O2 sensor... that is all done from above the car correct? Or is the disconnect done next to that donut gasket where the DP meet the midpipe?

[rsmrk3]

Originally Posted by Azurite_F80

To unclip the O2 sensor... that is all done from above the car correct? Or is the disconnect done next to that donut gasket where the DP meet the midpipe?

This is done on the downstream O2 Sensors, below the car- So, next to that donut gasket where the DP meet the midpipe.

[jukuto]

Originally Posted by maxbeilke

Used this method today to pass in Illinois. We are allowed 1 not ready. I got everything to ready up except the catalyst and passed. Thanks a lot.

Where did you get tested? Im in Illinois as well and I failed twitce with all the monitors ready except for the catalyst monitor.

[rsmrk3]

Originally Posted by jukuto

Where did you get tested? Im in Illinois as well and I failed twitce with all the monitors ready except for the catalyst monitor.

I think if catalyst monitor is not ready, EVAP also won't be ready.
If you are confidant that's not the case, make sure you are not clearing codes before you go to inspection because if you clear code for catalyst monitor (or any engine code) all monitors will get reset.

[maxbeilke]

Originally Posted by jukuto

Where did you get tested? Im in Illinois as well and I failed twitce with all the monitors ready except for the catalyst monitor.

The one in Skokie. If you only have 1 not ready and no check engine light you should pass.

[jukuto]

Originally Posted by rsmrk3

I think if catalyst monitor is not ready, EVAP also won't be ready.
If you are confidant that's not the case, make sure you are not clearing codes before you go to inspection because if you clear code for catalyst monitor (or any engine code) all monitors will get reset.

Evap monitor was ready for me.
I also didn’t clear any codes.
The only thing i’ve done is install the defouler as I thought that would get the cat monitor ready.

[jukuto]

Originally Posted by maxbeilke

The one in Skokie. If you only have 1 not ready and no check engine light you should pass.

I called the emissions place in Skokie to check. The lady I talked to told me that one monitor can be “Not Ready” as long as it isn’t the catalyst monitor. So maybe you got lucky when you went.
Also, I have no check engine light.

[maxbeilke]

Originally Posted by jukuto

I called the emissions place in Skokie to check. The lady I talked to told me that one monitor can be “Not Ready” as long as it isn’t the catalyst monitor. So maybe you got lucky when you went.
Also, I have no check engine light.

Doesn’t sound right to me. I’ve passed the last 2 tests with the catalyst not ready.

[rsmrk3]

Originally Posted by jukuto

Evap monitor was ready for me.
I also didn’t clear any codes.
The only thing i’ve done is install the defouler as I thought that would get the cat monitor ready.

If you installed defouler on downstream sensor(s), it should work. Are you on stock tune? If so, you probably need to drive it more for the Cat monitor to get ready.

If you are on aftermarket tune, double check if you turned off Cat monitors on the Tune- this needs to be on for the Cat monitor to get ready.

[Jonb70]

Were you able to install the defoulers without taking off the downpipes? I’m in an unfortunate situation where I only installed 1 defouler on each o2.

[Kinem4tics.media]

I just went through the same situation and thought I might add a small piece of useful information.

For context I have a 2015 f82 m4 with high flow catted (400 cell) turner motorsport downpipes, turner mid pipes and turner valved catback exhaust. Turner told me there is a 50% chance that the high flow catted downpipes would throw a check engine light (from my experience and talking to others, it is 100% chance it will throw a check engine lol).

The spacers/defoulers unfortunately will not fit with the turner catted down pipes just with how the cats are placed- its too tight.

My next next option was to get 90 degree mini cat adapter. Here is the link: https://drifthq.com/products/pro-spo...sor-cel-fix-91

I read on this thread that you could potentially leave your car tuned to stage 2, turn on the catalytic monitor and with the mini cats you wouldn't throw a light. Unfortunately, that was not that case. I went through 3 drive cycles and every time my check engine light would come on. It was not until I flashed back to the stock tune with the mini cats that I was able to pass inspection.

Moral of the story- I would recommend flashing back to your stock tune even though folks said it is not needed.

[HotRodM4]

Originally Posted by Kinem4tics.media

I just went through the same situation and thought I might add a small piece of useful information.

For context I have a 2015 f82 m4 with high flow catted (400 cell) turner motorsport downpipes, turner mid pipes and turner valved catback exhaust. Turner told me there is a 50% chance that the high flow catted downpipes would throw a check engine light (from my experience and talking to others, it is 100% chance it will throw a check engine lol).

The spacers/defoulers unfortunately will not fit with the turner catted down pipes just with how the cats are placed- its too tight.

My next next option was to get 90 degree mini cat adapter. Here is the link: https://drifthq.com/products/pro-spo...sor-cel-fix-91

I read on this thread that you could potentially leave your car tuned to stage 2, turn on the catalytic monitor and with the mini cats you wouldn't throw a light. Unfortunately, that was not that case. I went through 3 drive cycles and every time my check engine light would come on. It was not until I flashed back to the stock tune with the mini cats that I was able to pass inspection.

Moral of the story- I would recommend flashing back to your stock tune even though folks said it is not needed.

Do you keep the mini cats on now that you passed or do you have to remove them? Would be great if you can leave if there no repercussions.

[NORAGRETS]

Originally Posted by 2015f82m4

Short Answer:

1) Install 'spark plug' defoulers on each downstream o2 sensor (stack 2 defoulers and then screw o2 sensor into defouler.)
2) Flash back to stock tune
3) Drive car around and complete drive cycle to get readiness monitors ready (can monitor using the vgate iar pro bluetooth 4.0 obd2 dongle and car scanner elm obd2 app using the 'emissions tests' feature'
4) Once monitors are ready and pass, go to emissions and pass
5) flash back to stage 2 and remove defoulers


Long answer:

I did a lot of research on these forums and I was unable to find any definitive answers on how to pass emissions without cats. I am running VRSF Catless Downpipes, Active Autowerke Midpipe and M Performance Exhaust. I am also tuned via BM3 Stage 2. I went through emissions very naive thinking since I didn’t have a CEL i would pass. Well I guess i just expected my readiness monitors to be set to ready since my fully built evo x with no cats, big turbo, external dump passed no issues. Turns out BM3, as most tuning software’s do, disable your oxygen sensor monitors so you don’t get a CEL. First time through I failed due to my monitors not being read (As seen in attached photos)

Methods to pass:
1) Defoulers
— I read many good and bad things about defoulers. They seemed to work 50/50 depending on the vehicle. Pro's are they are cheap and easy to install. I did see fabspeed had these super cool 'mini cats' inside the defoulers. The only thing was they are $225 for a set

2) o2 Simulators
Area 74 makes these. Cons are they are 120 and f80/f82 has 2 downstream o2 sensors so that’s [...]

I’ve been running catless since 2012 on my E82 and since 2022 on my F80, able to pass Massachusetts emissions every year.

It’s a pain in the dick some years and others it’s easy. But my method is flash to stock tune, plug in a OBD2 scan tool (I have a cheap one from harbor freight cost like $50 or less).

Basically: reset/clear all the monitors and drive the car with the scan tool plugged in until you get “ready” readings on everything EXCEPT for the O2 and CAT…this is where it can go one way or the other…basically you just wanna keep driving until the O2 reads as ready, as the CAT will obviously never read as ready.

Mass allows 1 monitor to be “not ready” so as soon as that O2 monitor is good to go I go to the nearest station and get a sticker lol.

I’ve had drive cycles be OVER 800 miles some years which is absurd, and others it’s been like 20-30 miles.

I just go about my normal driving and day and every now and again I check the scan tool to see where I’m at.

If the CAT monitor lights up as fail before the 02 I reset and start over.

Not for everyone, but it works

[MasterYous]

Hopefully adding some useful info to this thread. I use MHD so I reached out to them about all of this and here is what Martial said:

- under DME codes you will see all of the emissions info that you need (I attached a screenshot of what it looks like) - this means you probably do not need a third party app nor another OBDII adapter.

- The downpipes option under "Options" when you flash a tune has two settings, Catless, or Stock/OEM/Catted. All you have to do is pick the Catted option and it will leave the O2/Cat sensor ON regardless of if you have a tune or not. You do not need to flash back to stock (and should NOT if you have a locked DME).

- I'm currently in the middle of my first drive cycle WITHOUT defoulers and I've managed to get everything ready except Catalyst and O2 Heater. I live in VA so you're allowed one Incomplete.

- If you're getting error codes other than Catalytic efficiency being below the limit, you probably have something else going on besides emissions, such as a bad O2 sensor. You have to be really really careful not to torque and spin the O2 cables when you disconnect and reconnect them from the pipes. Always unplug your sensor plugs from the harnesses before disconnecting the physical sensor on the DP bungs. If you're putting defoulers on, unplug the harness from under the car's belly pan and FULLY UNCLIP the O2 sensor cables and let them hang loose BEFORE you remove the O2 sensor itself. Just the downstream O2 sensors, not the ones in the engine bay - because you are not going to remove the pre-cat sensor closest to the turbo!

I need one more to get ready but I haven't driven around enough to know if a defouler will be needed. I am using ARM resonated catless DPs and I think there will be enough room under the car to install them, if needed.

tl;dr: if you use a modern version of the MHD app, you should not need any third party apps and you can enable/disable the sensor directly when you flash.