[softbox]

Just for my own clarification, after Cobb's recent announcement, am I correct in understanding that moving forward, 2019+ STI's with a Cobb catted downpipe would NOT be able to be protuned/e-tuned without a CEL now?

Currently running an OTS map (stock 19' STI with only a catted downpipe), and weighing my options for tuning.

 

[ntg44]

Just for my own clarification, after Cobb's recent announcement, am I correct in understanding that moving forward, 2019+ STI's with a Cobb catted downpipe would NOT be able to be protuned/e-tuned without a CEL now?

Currently running an OTS map (stock 19' STI with only a catted downpipe), and weighing my options for tuning.

Yep, that's correct if using Cobb Accessport, until a catted downpipe that passes O2 readiness is found. I've been trying to find a solution for the past 6 months to pass the rear O2 monitor. I've tried multiple cats, the catted O2 spacer, and so far haven't been successful.

My last resort is actually finding a GESi gen 2 cat to weld in and test, but my hunch is that since Cobb themselves have halted development on the 19+ STI catted downpipe, the GESI gen 2 cat won't work either. I'm sure they've tried.

If anyone has a lead on a GESi Gen 2, part 50230, please PM me, I'm willing to take the ~$500 gamble to try it. But right now the only method I've found is to buy a Supra downpipe for $1300 only to cut it out and weld in my downpipe, and frankly, that's ridiculous. Any place I contact says 10+ week lead time for the part, and after I cancelled my last order after 12 weeks of waiting, I'm convinced they're not even shipping them out right now.

 

[Jay11STI]

Yep, that's correct if using Cobb Accessport, until a catted downpipe that passes O2 readiness is found. I've been trying to find a solution for the past 6 months to pass the rear O2 monitor. I've tried multiple cats, the catted O2 spacer, and so far haven't been successful.

My last resort is actually finding a GESi gen 2 cat to weld in and test, but my hunch is that since Cobb themselves have halted development on the 19+ STI catted downpipe, the GESI gen 2 cat won't work either. I'm sure they've tried.

If anyone has a lead on a GESi Gen 2, part 50230, please PM me, I'm willing to take the ~$500 gamble to try it. But right now the only method I've found is to buy a Supra downpipe for $1300 only to cut it out and weld in my downpipe, and frankly, that's ridiculous. Any place I contact says 10+ week lead time for the part, and after I cancelled my last order after 12 weeks of waiting, I'm convinced they're not even shipping them out right now.

Another option would be grimmspeed. They just announced a new catted J pipe for the FA20 wrx. Supposedly no check engine light. Grimmspeed also said they are trying to incorporate that same cat into an EJ downpipe.

So even with oxygen sensor spacer, obd readiness for that monitor wont set? Did I miss understand that? Have you tried doing the drive cycle in order to set the readiness monitor?

 

[ntg44]

Another option would be grimmspeed. They just announced a new catted J pipe for the FA20 wrx. Supposedly no check engine light. Grimmspeed also said they are trying to incorporate that same cat into an EJ downpipe.

So even with oxygen sensor spacer, obd readiness for that monitor wont set? Did I miss understand that? Have you tried doing the drive cycle in order to set the readiness monitor?

The way I have been testing is that I have 2 different versions of my tune, with P0420 enabled on one and disabled on the other. When I made each of these changes, I flashed the tune with the code enabled and performed a driving cycle. In all cases, P0420 came on, with the exception of the mini catted spacer where I got the rear O2 low voltage code instead. So a drive cycle was completed in each case.

After my 20g build was tuned, I thought ahead after getting P0420 the first time to get the 2 versions. Of course the shop/tuner I consulted with said there would be no problem with any of this, which is why I decided to follow through with this build in the first place. And as always given my luck, I now have the exact issue I was trying to avoid. The 400 whp is great, but I would not have gone through with this had I known I'd have both Oxygen and EGR monitors in not ready state. The STI doesn't even have EGR so I have no idea how the monitor can be in not ready. And nobody I talk to knows how to fix it.

Given the fact that Cobb has now locked down their software, it doesn't look like resolving either of these monitors is going to be feasible without hardware changes. I'm at a point where if I can't find a gesi gen 2 cat, which isn't even guaranteed to work, I'm ripping everything out and going back to a stage 1 like custom tune.

Unless someone wants a killer deal on a 20g flex fuel 2020 STI with 4800 miles haha. I'm more than willing to part with the car at this point to someone who doesn't have emissions testing in their area. Wasted so much money getting to this point and now I need to spend even more to rip it all out again.

 

[magnetite2020sti]

You know the 19 up got better factory Dp? Lol. Why are people under 500 whp so concerned over modified exhaust BS…? Why does 10-15 whp make a F’in difference in the end if your shit is jacked up for emissions? lol.

 

[Jay11STI]

The way I have been testing is that I have 2 different versions of my tune, with P0420 enabled on one and disabled on the other. When I made each of these changes, I flashed the tune with the code enabled and performed a driving cycle. In all cases, P0420 came on, with the exception of the mini catted spacer where I got the rear O2 low voltage code instead. So a drive cycle was completed in each case.

After my 20g build was tuned, I thought ahead after getting P0420 the first time to get the 2 versions. Of course the shop/tuner I consulted with said there would be no problem with any of this, which is why I decided to follow through with this build in the first place. And as always given my luck, I now have the exact issue I was trying to avoid. The 400 whp is great, but I would not have gone through with this had I known I'd have both Oxygen and EGR monitors in not ready state. The STI doesn't even have EGR so I have no idea how the monitor can be in not ready. And nobody I talk to knows how to fix it.

Given the fact that Cobb has now locked down their software, it doesn't look like resolving either of these monitors is going to be feasible without hardware changes. I'm at a point where if I can't find a gesi gen 2 cat, which isn't even guaranteed to work, I'm ripping everything out and going back to a stage 1 like custom tune.

Unless someone wants a killer deal on a 20g flex fuel 2020 STI with 4800 miles haha. I'm more than willing to part with the car at this point to someone who doesn't have emissions testing in their area. Wasted so much money getting to this point and now I need to spend even more to rip it all out again.

I see now. You are correct that sti doesnt have egr. When it comes to OBD monitor readiness there are certain drive cycles that can be performed a certain way to set those monitors. Subaru tends to lump a couple of monitors together sometimes. I believe EGR, oxygen sensor and also EVAP can all be lumped together in one drive cycle. Normally every time you clear faults, battery reset, and or even reflash a tune, the monitors all get reset.

I just had to get my monitors ready myself this past weekend due to disconnecting my battery from some electronic work. Anyways I was able to get them ready all in 1 attempt. If you havent done this, give it a shot.

1. Let the car sit overnight, door locked of course.
2. Cold start and let idle for 20 seconds
3. Immediately drive the car
4. Try to drive for atleast 15mins at 50 - 60mph
5. Try to reduce downshifting and heavy throttle changes and inputs.
6. Coast with foot off gas pedal to 15 mph without downshifting
7. Make sure you have more than a quarter tank of fuel
8. Do not refuel during this process.
9. Make sure check engine light is off prior to starting this process.

Pretty much just get on the highway and straight cruise nice and easy. After your 15mins of cruising, take an exit ramp and just coast to 15mph before stopping. I was able to set all my monitors with just this drive cycle. All in all it probably took me like half an hour or so on my little trip on a Sunday. BTW here in NJ we are allowed 1 monitor not to be ready just incase you are in my state.

 

[softbox]

According to a couple different online subaru parts places, it seems the downpipe assembly (which collectively contains the "catalytic converter" part #44612AA370 and the "converter & pipe" part #44611AA250) are the same part numbers across 2015-2020 base/Limited STi's (didn't check 2021/RA's/S209's). However, the midpipe and mufflers were re-designed starting in 2019+, and have a different part number than the 2015-2018. Maybe the redesigned midpipe and mufflers is where the extra +5hp difference comes in between the years.

Either way, there are probably still some gains to be had with the Cobb downpipe vs OEM. My car came with a downpipe installed, so I would love to be able to tune for it. But I do have the OEM just in case.

 

[ntg44]

I see now. You are correct that sti doesnt have egr. When it comes to OBD monitor readiness there are certain drive cycles that can be performed a certain way to set those monitors. Subaru tends to lump a couple of monitors together sometimes. I believe EGR, oxygen sensor and also EVAP can all be lumped together in one drive cycle. Normally every time you clear faults, battery reset, and or even reflash a tune, the monitors all get reset.

I just had to get my monitors ready myself this past weekend due to disconnecting my battery from some electronic work. Anyways I was able to get them ready all in 1 attempt. If you havent done this, give it a shot.

1. Let the car sit overnight, door locked of course.
2. Cold start and let idle for 20 seconds
3. Immediately drive the car
4. Try to drive for atleast 15mins at 50 - 60mph
5. Try to reduce downshifting and heavy throttle changes and inputs.
6. Coast with foot off gas pedal to 15 mph without downshifting
7. Make sure you have more than a quarter tank of fuel
8. Do not refuel during this process.
9. Make sure check engine light is off prior to starting this process.

Pretty much just get on the highway and straight cruise nice and easy. After your 15mins of cruising, take an exit ramp and just coast to 15mph before stopping. I was able to set all my monitors with just this drive cycle. All in all it probably took me like half an hour or so on my little trip on a Sunday. BTW here in NJ we are allowed 1 monitor not to be ready just incase you are in my state.

Thank you for the suggestion. I will try your method, but so far I have driven over 1000 miles on my tune (without reflash/resetting monitors) and can get every monitor to "READY" state except O2 and EGR. I can only guess at this point that the EGR readiness is related to the O2 monitor, the TGV deletes, or the tune itself.

The only one out of the 3 that I have somewhat control over is the rear O2. I did not plan on having my TGVs deleted, but I found out after the fact that they were removed in order to power the flex fuel sensor on one side, and according to my builder, the fuel pressure regulator on the other. I am not using Cobb's FPR per the recommendation of the shop/tuner. And now that Cobb locked everything down, revising the tune using Accessport is not an option. So I'm kind of stuck until I can get either O2 or EGR monitor in "READY" state. But I will try your suggestion, it can't hurt at this point.

I suppose I asked for this headache, but I really hate being lied to that this would be a problem free build as far as emissions testing, only to find out that I now have a problem that of course the shop nor anyone else can figure out a solution to. I would not have gone through with this had I not been completely reassured that this wouldn't happen.

If anyone with a 19+ STI has their oxygen monitor in "READY" state with any non-stock downpipe, seriously, PM me. I haven't found a single owner yet. Or even a 20g build with their EGR monitors in READY state. Otherwise I don't see any solution but to go back to stock downpipe and TGVs, which means ripping out basically everything.

 

[AustinSedz]

Thank you for the suggestion. I will try your method, but so far I have driven over 1000 miles on my tune (without reflash/resetting monitors) and can get every monitor to "READY" state except O2 and EGR. I can only guess at this point that the EGR readiness is related to the O2 monitor, the TGV deletes, or the tune itself.

The only one out of the 3 that I have somewhat control over is the rear O2. I did not plan on having my TGVs deleted, but I found out after the fact that they were removed in order to power the flex fuel sensor on one side, and according to my builder, the fuel pressure regulator on the other. I am not using Cobb's FPR per the recommendation of the shop/tuner. And now that Cobb locked everything down, revising the tune using Accessport is not an option. So I'm kind of stuck until I can get either O2 or EGR monitor in "READY" state. But I will try your suggestion, it can't hurt at this point.

I suppose I asked for this headache, but I really hate being lied to that this would be a problem free build as far as emissions testing, only to find out that I now have a problem that of course the shop nor anyone else can figure out a solution to. I would not have gone through with this had I not been completely reassured that this wouldn't happen.

If anyone with a 19+ STI has their oxygen monitor in "READY" state with any non-stock downpipe, seriously, PM me. I haven't found a single owner yet. Or even a 20g build with their EGR monitors in READY state. Otherwise I don't see any solution but to go back to stock downpipe and TGVs, which means ripping out basically everything.

Kind of echoing another thread; have you talked to your tuner about tuning with opensource?
Do they do this?
Essentially it's loading the tune directly onto the ECU without using Cobb's Accessport or software suite.
Opensource doesn't have the issue that Cobb is facing with the EPA, so the O2 and TCV parameters are not locked.

My local tuner (Neetronics) who is a Subaru specialist tunes Cobb, opensource, standalone, everything, because they literally see 1000's of variations of EJ/FA and need to have the flexibility to tune and adjust in every scenario.

I know with the old old STi's, opensource was a very common practice before Cobb swooped in and gobbled up the market with their convenience and ease of use.

 

[Jay11STI]

Thank you for the suggestion. I will try your method, but so far I have driven over 1000 miles on my tune (without reflash/resetting monitors) and can get every monitor to "READY" state except O2 and EGR. I can only guess at this point that the EGR readiness is related to the O2 monitor, the TGV deletes, or the tune itself.

The only one out of the 3 that I have somewhat control over is the rear O2. I did not plan on having my TGVs deleted, but I found out after the fact that they were removed in order to power the flex fuel sensor on one side, and according to my builder, the fuel pressure regulator on the other. I am not using Cobb's FPR per the recommendation of the shop/tuner. And now that Cobb locked everything down, revising the tune using Accessport is not an option. So I'm kind of stuck until I can get either O2 or EGR monitor in "READY" state. But I will try your suggestion, it can't hurt at this point.

I suppose I asked for this headache, but I really hate being lied to that this would be a problem free build as far as emissions testing, only to find out that I now have a problem that of course the shop nor anyone else can figure out a solution to. I would not have gone through with this had I not been completely reassured that this wouldn't happen.

If anyone with a 19+ STI has their oxygen monitor in "READY" state with any non-stock downpipe, seriously, PM me. I haven't found a single owner yet. Or even a 20g build with their EGR monitors in READY state. Otherwise I don't see any solution but to go back to stock downpipe and TGVs, which means ripping out basically everything.

I see. Driving 1000 miles may not be enough if the procedure isnt done right. Try my method and or refer to this. There is also a second procedure if the first method doesn't work. This is pretty much where I got it from and it worked for me.

I didnt have any issues getting my monitors ready. However, I still have my stock oem tgv's and still run pump 93 fuel. I am at stage 2+ with ELH and some fueling mods. Protuned of course

 

[ntg44]

Okay, OP to answer your question completely, I actually called Cobb today to find the reason they discontinued development on the 19+ STI downpipe. My suspicion was correct. They could not find any cat that would prevent P0420 CEL from appearing, so that's why they are no longer developing a downpipe for 19+ STIs.

So in conclusion, as of today, if you have any other cat on your 19+ STI other than what's in the stock downpipe, you are not going to be able to get the code tuned out via Cobb software. Maybe there will be a cat in the future that passes, but looks like the days of aftermarket downpipes are over for the newer model years. At least my search for a Gen 2 GESi cat is over.

 

[chechem84]

Had the same problem. Had a March tune with the DP. No codes. Added an intake in May. Got code with new tune. I went with a Botti tune both times. 35 miles and got the code. Mike adjusted o2 scaling and 30 miles no code. I am going to drive today and report back, but my scan tool showed all sensors ready and no pending. Might be a solution for you to go Botti tune to fix I can keep my light off. My AFR and corrections looked ok. I did a few key cycles as well. Will do more checking on my way home to see if everything AP and scan tool looks good.

 

[Jay11STI]

Had the same problem. Had a March tune with the DP. No codes. Added an intake in May. Got code with new tune. I went with a Botti tune both times. 35 miles and got the code. Mike adjusted o2 scaling and 30 miles no code. I am going to drive today and report back, but my scan tool showed all sensors ready and no pending. Might be a solution for you to go Botti tune to fix I can keep my light off. My AFR and corrections looked ok. I did a few key cycles as well. Will do more checking on my way home to see if everything AP and scan tool looks good.

I recommend Mikey to everyone. Ive gotten 2 tunes from him and both are great. Of course this was before all of the Cobb stuff happened.

 

[chechem84]

 

[ntg44]

Thanks for the comments @chechem84 . Unfortunately my situation is a little more complicated with the recent Cobb changes.

My EGR and rear O2 monitors are not ready, and I have TGV deletes installed. Regardless of why the monitors won't go ready, any future revisions to my tune would enable the TGV CELs, so my only options right now are hardware changes. And I'd much rather try downpipe hacks than go through TGV reinstallation with a follow up tune. Just more cost effective and practical. I've already spent more than I cared for getting to this point, so now I'm trying to minimize the impact to my wallet.

I spoke with my fabricator about this last night, and he's all in on making a downpipe section with the stock cat that can be hot swapped with V bands. This way it's not an annoying job to remove the whole downpipe, and turns into a comparatively painless 15 minute job done twice every 2 years in my case. I still have 3 years until my first emissions test, so I may not get to implementing this for a while, but I like to be prepared so I'm not scrambling later with a part out. It also gives the aftermarket time to potentially develop a more comprehensive workaround. Ideally I'd like a "do it once and it's done" solution, but that's how these things go sometimes.

 

[chechem84]

Thanks for the comments @chechem84 . Unfortunately my situation is a little more complicated with the recent Cobb changes.

My EGR and rear O2 monitors are not ready, and I have TGV deletes installed. Regardless of why the monitors won't go ready, any future revisions to my tune would enable the TGV CELs, so my only options right now are hardware changes. And I'd much rather try downpipe hacks than go through TGV reinstallation with a follow up tune. Just more cost effective and practical. I've already spent more than I cared for getting to this point, so now I'm trying to minimize the impact to my wallet.

I spoke with my fabricator about this last night, and he's all in on making a downpipe section with the stock cat that can be hot swapped with V bands. This way it's not an annoying job to remove the whole downpipe, and turns into a comparatively painless 15 minute job done twice every 2 years in my case. I still have 3 years until my first emissions test, so I may not get to implementing this for a while, but I like to be prepared so I'm not scrambling later with a part out. It also gives the aftermarket time to potentially develop a more comprehensive workaround. Ideally I'd like a "do it once and it's done" solution, but that's how these things go sometimes.

Understood. Emissions states are hard. I happen to live in one that a county doesn't require it, and Maine is looking at ripping out inspections all together.

 

[chechem84]

Thanks for the comments @chechem84 . Unfortunately my situation is a little more complicated with the recent Cobb changes.

My EGR and rear O2 monitors are not ready, and I have TGV deletes installed. Regardless of why the monitors won't go ready, any future revisions to my tune would enable the TGV CELs, so my only options right now are hardware changes. And I'd much rather try downpipe hacks than go through TGV reinstallation with a follow up tune. Just more cost effective and practical. I've already spent more than I cared for getting to this point, so now I'm trying to minimize the impact to my wallet.

I spoke with my fabricator about this last night, and he's all in on making a downpipe section with the stock cat that can be hot swapped with V bands. This way it's not an annoying job to remove the whole downpipe, and turns into a comparatively painless 15 minute job done twice every 2 years in my case. I still have 3 years until my first emissions test, so I may not get to implementing this for a while, but I like to be prepared so I'm not scrambling later with a part out. It also gives the aftermarket time to potentially develop a more comprehensive workaround. Ideally I'd like a "do it once and it's done" solution, but that's how these things go sometimes.

Not ready usually indicates a fault correct? If you have a more advanced scan tool you could see if you even getting values off the rear o2.

 

[ntg44]

Not ready usually indicates a fault correct? If you have a more advanced scan tool you could see if you even getting values off the rear o2.

Well yes, technically, but I have a few codes disabled (including P0420) due to the downpipe and TGV deletes. I have 2 versions of my tune with P0420 enabled and disabled, so I can test the catalyst by flashing the tune with the code enabled and waiting for a CEL to pop up or monitor to become ready. So at least I don't need to drive with the dash lit up nonstop.

 

[Jay11STI]

Understood. Emissions states are hard. I happen to live in one that a county doesn't require it, and Maine is looking at ripping out inspections all together.

Wow that crazy. I think inspections are intended to be good but focus on the wrong stuff in my opinion. They should focus on safety items and vehicle condition. Things that prevent cars from being considered safe to drive on the road. Here in NJ all they care about is check engine light, OBD monitors, and emissions. You can literally roll in with bald tires and leaking brake lines and as long as the ecu meets that criteria, you get a sticker. Amazing isn't it.....

 

[AustinSedz]

Wow that crazy. I think inspections are intended to be good but focus on the wrong stuff in my opinion. They should focus on safety items and vehicle condition. Things that prevent cars from being considered safe to drive on the road. Here in NJ all they care about is check engine light, OBD monitors, and emissions. You can literally roll in with bald tires and leaking brake lines and as long as the ecu meets that criteria, you get a sticker. Amazing isn't it.....

we had the obd emissions for about 4 years, then that gov got voted out and they scrapped it.
they literally had staff at a dealership who were paid and trained to drive cars all day to hit ‘ready’ status so they could be passed for sale. Tell me, how is that protecting the environment? Lol

We also just scrapped reg fees for license plate stickers, so while u do need to keep up on ur registrations, no more 120$ stickers every year 😆

for us, safety is necessary to register the car, but once it’s plated it’s good till u sell again!
Personally, i think this is more important than emissions and they should do these inspections every 3-5 years.
That’ll help stop all the lifted mall crawlers and tilty boys 😂

really, most cars that would fail emissions are old beaters that would be rusting and falling apart, or regular cars that are obviously broken so a safety would pick up the issue anyways.
A CEL alone wouldnt pass safety, and most emissions issues trigger a CEL 🤷🏻‍♂️