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2020 STI---I've talked to a E Tuner around my way (will not post the name of tuner) who informed me that they would E tune my car but I would be stuck with a CEL due to the Cobb Gesi Downpipe I am new to tuning of any vehicle and wanted to know if this was the consensus amongst most E tuners? If so would having it tuned on the dyno solve the issue or are there any reputable E tuners in the community that could work with me. I have a bunch of parts I have been collecting for a year or so that want to put on the car. Any information or help would be great thanks in advance
 

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I am e-tuned with that DP and no cel. I have a 2015. Not sure if that changes anything. I used BrenTuning btw, he was easy to work with.
 

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I think you may need to look into contacting another tuner. There have been hundreds to thousands of us running downpipes and protunes throughout the years without having a check engine light on. That also including catless set ups. A dyno tune wont solve your issue, its all in the tuner and their abilities. I would make sure that whoever you're going to is a Cobb certified protuner.
 

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Id like to retract my previous statement and also insert foot into mouth.

 

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OP, I might be able to help with an answer. From my experience in my 2020 STI, the Cobb GESI downpipe does not work on 19+. It is the Gen 1 300 cell cat that is the problem.

Cobb has also discontinued development of a new downpipe for 19+ STIs if you read their Green Speed updates carefully. I have been installing different cats to see if any would work, but so far I have had zero success. The GESI Gen 2 400 cell cats are unavailable practically speaking. I waited 12 weeks and ended up cancelling my order.

My only option after 5 months of searching has been to buy a Supra GESI Gen 2 downpipe from Active Autowerke for $1300 and cut out the cat to weld into my downpipe. That's the only part readily available that has the Gen 2 cat that's technically supposed to work. But considering Cobb has discontinued development of a new downpipe for 19+, my intuition tells me even that isn't enough. And I'm not going to spend and potentially lose $1300+ to find out.

Sucks, but that's just my experience based on trying to get something that will pass the rear O2. We're SOL for the time being.
 

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OP, I might be able to help with an answer. From my experience in my 2020 STI, the Cobb GESI downpipe does not work on 19+. It is the Gen 1 300 cell cat that is the problem.

Cobb has also discontinued development of a new downpipe for 19+ STIs if you read their Green Speed updates carefully. I have been installing different cats to see if any would work, but so far I have had zero success. The GESI Gen 2 400 cell cats are unavailable practically speaking. I waited 12 weeks and ended up cancelling my order.

My only option after 5 months of searching has been to buy a Supra GESI Gen 2 downpipe from Active Autowerke for $1300 and cut out the cat to weld into my downpipe. That's the only part readily available that has the Gen 2 cat that's technically supposed to work. But considering Cobb has discontinued development of a new downpipe for 19+, my intuition tells me even that isn't enough. And I'm not going to spend and potentially lose $1300+ to find out.

Sucks, but that's just my experience based on trying to get something that will pass the rear O2. We're SOL for the time being.
what do you mean it "doesnt work", that downpipe should fit right up on the 19+ sti so far as I undersand. not sure what's wrong with the cat in it....
 

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what do you mean it "doesnt work", that downpipe should fit right up on the 19+ sti so far as I undersand. not sure what's wrong with the cat in it....
What it means is you'll end up with a P0420 CEL code on a 19+ and you can't pass emissions. It bolts up just fine - I have it installed on my 2020. That doesn't mean it won't throw a CEL. 2019+ have stricter emissions requirements that the Cobb GESI downpipe doesn't address. And I'm not even sure the Gen 2 GESI cat will work either, given that Cobb's given up on it.
 

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What it means is you'll end up with a P0420 CEL code on a 19+ and you can't pass emissions. It bolts up just fine - I have it installed on my 2020. That doesn't mean it won't throw a CEL. 2019+ have stricter emissions requirements that the Cobb GESI downpipe doesn't address. And I'm not even sure the Gen 2 GESI cat will work either, given that Cobb's given up on it.
oh ok, if you can find a tuner to delete that code so it wont show up you'd be good, but that's assuming you dont live in CA lol. and that you can find a tuner that's willing to do it. but at this point the accessport wouldnt be able to be used for that, it would have to be opensource from what i'm understanding.
 

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So would all of this now make EcuTek the go to for our platform? Being located in the UK I imagine they can't sell directly to the US, but creative people could run their tunes?
i'm about 80% sure ecutek and cobb are owned by the same parent company, so ecutek would likely follow what cobb is doing shortly. meaning for tuning IF you have any emmissions related codes that need to be deleted, you'd be stuck open source or going full standalone to tune it properly moving forward. if you have a tune already with these codes deleted, and are not going to do any further mods, you'd be ok just leaving the tune you already have, but if you plan on doing more mods/tuning, you'd need to leave all the emmissions related items on the car. at least that's what i'm understanding as of now. I may not be 100% correct in this. still reading/understanding
 

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oh ok, if you can find a tuner to delete that code so it wont show up you'd be good, but that's assuming you dont live in CA lol. and that you can find a tuner that's willing to do it. but at this point the accessport wouldnt be able to be used for that, it would have to be opensource from what i'm understanding.
The P0420 code is deleted/deactivated in my case, but the O2 sensor remains in "NOT READY" state even with the code suppressed. That's the problem. Some states you're allowed 1 monitor not ready with no active CELs, but right now I'm at 2. Rear O2 and EGR monitors are both in not ready state. I have yet to find a solution or cause of the EGR monitor readiness. My only delete is the TGVs.

Either way, the point is that the OP won't have luck with any catted downpipe as far as I'm concerned if they need to pass emissions (unless 1 not ready is permitted where they are). Otherwise, finding a tuner using a tool other than Cobb to suppress the code is the only option they have if they do not have emissions testing.

In my case, I'm done experimenting. I haven't been able to find a high flow cat that won't throw a CEL, and I'm only willing to spend so much money and time trying to find one that will. I'd rather just go back to stock turbo, downpipe, and TGVs and get a custom tune to get the most out of whatever it can on 93, which isn't much compared to where I'm at now. But it's headache free.
 

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The P0420 code is deleted/deactivated in my case, but the O2 sensor remains in "NOT READY" state even with the code suppressed. That's the problem. Some states you're allowed 1 monitor not ready with no active CELs, but right now I'm at 2. Rear O2 and EGR monitors are both in not ready state. I have yet to find a solution or cause of the EGR monitor readiness. My only delete is the TGVs.

Either way, the point is that the OP won't have luck with any catted downpipe as far as I'm concerned if they need to pass emissions (unless 1 not ready is permitted where they are). Otherwise, finding a tuner using a tool other than Cobb to suppress the code is the only option they have if they do not have emissions testing.

In my case, I'm done experimenting. I haven't been able to find a high flow cat that won't throw a CEL, and I'm only willing to spend so much money and time trying to find one that will. I'd rather just go back to stock turbo, downpipe, and TGVs and get a custom tune to get the most out of whatever it can on 93, which isn't much compared to where I'm at now. But it's headache free.
ohh see that makes more sense. i'm in a rural area and dont have to do emmissions (safety inspector does have to see a cat on the car to pass that, but that's all)
 

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In my case, I'm done experimenting. I haven't been able to find a high flow cat that won't throw a CEL, and I'm only willing to spend so much money and time trying to find one that will. I'd rather just go back to stock turbo, downpipe, and TGVs and get a custom tune to get the most out of whatever it can on 93, which isn't much compared to where I'm a
Tool Nickel Cylinder Metal Auto part

Catted o2 spacer.
Works for catless headers on many other cars, so if you're still having issues with the race cat on the 19+, this will probably 'bump it up' to enough filtration to not throw a code.
Not very expensive either...
It's an emissions 'cheat' which is probably why Cobb doesn't explore this avenue, otherwise people would raise the question 'so this works catless, right?' lol

I'd expect the GESI cats to throw codes easier than the old one as they actually flow more than before, which is counter to tighter o2 readings.
Better for power, worse for CEL's on a sensitive sensor
 

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View attachment 65915
Catted o2 spacer.
Works for catless headers on many other cars, so if you're still having issues with the race cat on the 19+, this will probably 'bump it up' to enough filtration to not throw a code.
Not very expensive either...
It's an emissions 'cheat' which is probably why Cobb doesn't explore this avenue, otherwise people would raise the question 'so this works catless, right?' lol

I'd expect the GESI cats to throw codes easier than the old one as they actually flow more than before, which is counter to tighter o2 readings.
Better for power, worse for CEL's on a sensitive sensor
Thanks for the suggestion, but I tried that already. It came up with another code after installing that. I don't remember the exact code but it was something about a low voltage reading on the rear O2 sensor.
 
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