How to pass emissions with catless downpipes

[TakeOne]

Originally Posted by M4_85

Seems like the oreilly ones work with no catted dp but has anybody tried resonated, I'm thinking I need the other defouler maybe

This was me to a T! I tried the cheap oreily ones, no luck. Then round 2 tried the mini-cat ones and it worked. I as well have AR resonated DP's too

[Ryguy29]

I have a tune . That works

[Bettertomorrow]

Every time I look at this thread, I am glad I didn't upgrade DP, such hassle. My car should be emission compliant with current setup and shouldn't even have to revert to stock for emission. When my stock DP goes, I will just get AA GESI and that will be that.

[M4_85]

Originally Posted by Bettertomorrow

Every time I look at this thread, I am glad I didn't upgrade DP, such hassle. My car should be emission compliant with current setup and shouldn't even have to revert to stock for emission. When my stock DP goes, I will just get AA GESI and that will be that.

Originally Posted by Bettertomorrow

Every time I look at this thread, I am glad I didn't upgrade DP, such hassle. My car should be emission compliant with current setup and shouldn't even have to revert to stock for emission. When my stock DP goes, I will just get AA GESI and that will be that.

Amen to that haha, I wish I knew before I got the dp, now I'm determined to make it work lol, who wants to downgrade from stage 2 to 1

[Info@mad-us.com]

Originally Posted by M4_85

Amen to that haha, I wish I knew before I got the dp, now I'm determined to make it work lol, who wants to downgrade from stage 2 to 1

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.

[M4_85]

Update I put big daddies mini cat in and the p0420 code is gone but i still have the p0157 low voltage so I'm assuming just my 02 sensor is no good….

[18BMWX5M]

Anyone have any idea how to get these two ready? I cleared all codes and still won't go ready.

[Info@mad-us.com]

Originally Posted by 18BMWX5M

Anyone have any idea how to get these two ready? I cleared all codes and still won't go ready.

Cleared and immediate fail? Are they plugged in?

[18BMWX5M]

Originally Posted by Info@mad-us.com

Cleared and immediate fail? Are they plugged in?

What do you mean plugged in? The sensors are there and connected as they should be. My friend has mini-cats on the rear oxygen sensors so this shouldn't be the cause for both of these issues. What is the catalyst system and how does one get that monitor ready for emissions testing?

[Info@mad-us.com]

Originally Posted by 18BMWX5M

What do you mean plugged in? The sensors are there and connected as they should be. My friend has mini-cats on the rear oxygen sensors so this shouldn't be the cause for both of these issues. What is the catalyst system and how does one get that monitor ready for emissions testing?

If cleared it should reset. If the mini cats are working it should change status after a few drive cycles.

[18BMWX5M]

Originally Posted by Info@mad-us.com

If cleared it should reset. If the mini cats are working it should change status after a few drive cycles.

He's had them in for since March and still nothing has changed for these two monitors. I have defoulers on my m4 and my catalyst is ready but my oxygen sensor is showing not ready. I think I have a bad sensor now but I passed. So not sure what else we should try here.

[WhiteF83]

I got a 2015 M4 F83 on bm3 stage 2 and i recently just put those defoulers on and put it back on stock tune. drove the car for around 60 miles around 11pm and got them all ready except evap. then went back home around 12:30 am. when i start the car back up around 9 am, catalyst, oxygen, oxygen heater went back to not ready. so who ever is doing the drive cycle, make sure to do it and then head straight to your local shop to get your inspection done and dont let your car cool back down or else you gotta do the drive cycle again

[JACKKKKK]

Just pass the NY inspection today. I got VRSF catless downpipe,STOCK midpipe and muffler. The shop owner gave me an OBD machine and told me if OS light were not flashing then the car can pass the inspection. i am in NY so i think one missing is fine. I don't have spark plug defouler installed.(the only flashing one is "CM") so if u have catless dowpipe, flash to stock tune, do the drive cycle, check every 10 min, when the machine are not flashing, go to the shop right now and do inspection, and you should be fine.

[Info@mad-us.com]

Originally Posted by JACKKKKK

Just pass the NY inspection today. I got VRSF catless downpipe,STOCK midpipe and muffler. The shop owner gave me an OBD machine and told me if OS light were not flashing then the car can pass the inspection. i am in NY so i think one missing is fine. I don't have spark plug defouler installed.(the only flashing one is "CM") so if u have catless dowpipe, flash to stock tune, do the drive cycle, check every 10 min, when the machine are not flashing, go to the shop right now and do inspection, and you should be fine.

[Bang Ding Ow]

Used the O2 spacers trick in NY and passed 2 days ago with VRSF catless DP’s.

Interestingly, the EVAP never showed ready when using the app that OP suggested. I got everything to show READY except that. But, when I used my friend’s OBD2 plug-in tool, all monitors showed green on every drive cycle after the O2 spacer install (I drove about 120 miles before heading to inspection). Not sure what the disconnect is there, but maybe it will help someone using this trick in the future to head to inspection with confidence

[Talicx]

My car would throw a CEL once I get all the monitor to ready state… this is so frustrating.


Anyone know how to keep Evap from being ready?

[Nicky_D]

Me again, just wanted to provide another update with some context.

I'm running VRSF Catless downpipes with a single mid pipe/no secondary cats. I had a bit more difficulty passing this year but was able to do it this morning. I used the app/scanner OP recommended. My first drive cycle after installing the spacers I got a bank 1 rich code. With this code present I could never get the catalyst to read ready so I cleared my codes and went on a long drive. This happened again but this time with a lean code and I had to clear codes, do another drive cycle. Once the catalyst was ready EVAP also flipped to ready shorty after and I had all passed in the app. It look me about 120 miles of easy driving on the stock tune to get everything in a ready state. Before my inspection I drove for about 15 mins, checked to confirm everything was passed and did not turn the car off before getting the inspection. Do your checks, keep it running and just go right to the sticker station. Something new I also noticed, there is a "tampering check" line on our inspection reports now. We do not do visual inspection in MA but I'm told if you have a tune suppressing a cel or have tried to code out your O2 sensors you will fail.

[Talicx]

Originally Posted by Nicky_D

Me again, just wanted to provide another update with some context.

I'm running VRSF Catless downpipes with a single mid pipe/no secondary cats. I had a bit more difficulty passing this year but was able to do it this morning. I used the app/scanner OP recommended. My first drive cycle after installing the spacers I got a bank 1 rich code. With this code present I could never get the catalyst to read ready so I cleared my codes and went on a long drive. This happened again but this time with a lean code and I had to clear codes, do another drive cycle. Once the catalyst was ready EVAP also flipped to ready shorty after and I had all passed in the app. It look me about 120 miles of easy driving on the stock tune to get everything in a ready state. Before my inspection I drove for about 15 mins, checked to confirm everything was passed and did not turn the car off before getting the inspection. Do your checks, keep it running and just go right to the sticker station. Something new I also noticed, there is a "tampering check" line on our inspection reports now. We do not do visual inspection in MA but I'm told if you have a tune suppressing a cel or have tried to code out your O2 sensors you will fail.

Did you let the car cool down after reset drive cycle?


Can you please text me 7023327795

[gwen_khantha]

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 $240 for a set but it is guaranteed to work.

3) Put the stock downpipes back on
Since i paid my buddy to do it, it would've cost me 250 to take off my catless downpipes and return to stock only to take them back off and reinstall the catless downpipes after the emissions testing. Pro is it is 100% guaranteed to work. Cons is that it'll cost me not only $500, but a lot of time and headache. If you can do your downpipes yourself it would save you the money but still time consuming and a pain.

I decided to go the cheapest route and buy vibrant o2 sensor defoulers off amazon which were about $23 each so $46 for the pair. i quickly realized upon getting my m4 on the lift that the only way they were going to thread on was if i took the downpipes off because there was no room to spin them on.

So plan B...go to O'Reilly's and get their cheap spark plug defoulers. Part number 42009 https://www.oreillyauto.com/shop/b/ignition---tune-up-16776/non-fouler-17555/76bbf7c4bb16
I purchased two of these (2come in 1 pack) so I had a total of 4 of these defoulers. I then removed my downstream o2 sensors and stacked two defoulers together and screwed the o2 sensor in and did the same for the other o2 sensors and then reinstalled them. The idea here was to space the o2 sensor out enough so it doesn't get a good reading of the 'post cat' exhaust gases. I saw some people drill out the first defouler the o2 sensor goes in but I didn't do that, I left them exactly as they came.

I then flashed BACK TO STOCK tune. I know some people didn't need to do this, they just set their monitors to on using the configure advanced settings (gear icon top right corner) in the stage 2 map in the bm3 tuning software. in my opinion, it's easier to just flash back to stock (no need to relock the DME, you can flash back to stock and keep the DME unlocked) and then you'll need to drive around to get your monitors ready (see below)

I then used my vgate icar pro bluetooth 4.0 obd2 adapter plugged it into my obd2 port (i already had one from coding my car with the bimmercode app). then on the app store i downloaded the car scanner elm obd2 app https://apps.apple.com/us/app/car-scanner-elm-obd2/id1259933623 and you can go to the 'emissions test' feature and it will tell you if your monitors are set to ready or not. You will need to drive your car to get your monitors ready (see drive cycle photo). You can keep the emissions testing function open and it will tell you if your monitors are ready or not and if they pass or fail as it updates every 30 seconds or so. After driving around, all my monitors were set to ready and pass!

You can see the photos I attached, as you can see the monitors before the defouler were set to not ready and then after the defouler and flash back to stock they were set to ready and passed. I also used the 'live data' feature and selected oxygen sensor 2 (bank 1 and 2) so i could see the upstream and downstream oxygen sensor voltage. The downstream o2 sensor was a little high at .080 V as it should be closer to 0.50 V but it was steady at idle and 'flat' and not up and down which is the graph of an oxygen sensor that is bad. If you look up the graph of oxygen sensors you will see what the upstream and downstream oxygen sensor voltage is supposed to look like and read. This is where an o2 simulator comes into play. It tricks the sensor into producing the correct voltages, but in this case the defouler worked just fine by spacing the o2 sensor away from the catless downpipe.

After all my emissions tests were set to pass and were green i went to emissions testing where I passed with no issues. The only part i had 'help' with was the 'visual inspection' although it would be pretty hard for a tech to see the primary cats in the downpipes since the undertray/splash guard covers up most of the downpipes. After doing so I re-flashed my car and I plan on removing the defoulers as it will mess with the o2 sensor values with the car running since it is a wideband sensor.

I can get u to pass without have to put stock cat on every time. Are u near Illinois?

[GritsNGravy]

Is there a video or visual instructions online anywhere for installing the defoulerS?

Planning on jacking the car up this weekend to take a stab at/

[thecooltype]

Originally Posted by JACKKKKK

Just pass the NY inspection today. I got VRSF catless downpipe,STOCK midpipe and muffler. The shop owner gave me an OBD machine and told me if OS light were not flashing then the car can pass the inspection. i am in NY so i think one missing is fine. I don't have spark plug defouler installed.(the only flashing one is "CM") so if u have catless dowpipe, flash to stock tune, do the drive cycle, check every 10 min, when the machine are not flashing, go to the shop right now and do inspection, and you should be fine.

Fellow nuer here... sending a dm for more info

[maxbeilke]

Originally Posted by gwen_khantha

I can get u to pass without have to put stock cat on every time. Are u near Illinois?

I’m in Illinois. Can you explain ?