[JermJermSti]

Hi i am looking for a catted downpipe for my car since going catless is a problem now and i want to know what downpipes i can use besides a gesi downpipe im not paying more than 700$ and are invited divorced downpipes fine???

 

[a5m]

Yea just send it you'll be fine.

 

[JermJermSti]

Yea just send it you'll be fine.

are you being serious?

 

[Karlot]

I don’t even think the gesi works without a protune.
And go bellmouth, not divorced

 

[PhoSho]

I don’t even think the gesi works without a protune.
And go bellmouth, not divorced

^What Karlot said and definitely go bellmouth.

I don't believe there are any aftermarket downpipes available, catted or not, that will work without eventually a triggering a CEL and they all will require a re-tune. If you have an accessport you could potentially find a pre-greenspeed OTS map that already has the P0420 disabled and just run that, but OTS tunes are generally not a great idea. I think your only good option would be OpenSource.

 

[Karlot]

^What Karlot said and definitely go bellmouth.

I don't believe there are any aftermarket downpipes available, catted or not, that will work without eventually a triggering a CEL and they all will require a re-tune. If you have an accessport you could potentially find a pre-greenspeed OTS map that already has the P0420 disabled and just run that, but OTS tunes are generally not a great idea. I think your only good option would be OpenSource.

you can protune for a catted downpipe through the accessport even post greenspeed, i know some are pickier than others, but you dont have to go opensource. so long as you retain your emissions equipment.

 

[dbwillis]

I had a few emails to tuners regarding regarding tuning and what downpipe they would suggest that wouldn't get them in trouble for running a non chatted car, and would let me pass emissions without a cel.
Both suggested GESI pipes, I picked up a Cobb v3

 

[dbwillis]

No cel after a week of driving, but I'm babying it until the 24th when it's set to get tuned.
Just using an ots map for now.
Also adding 1050 injectors, AEM fuel pump and Cobb regulator kit the same day.

 

[whatawhipur]

No cel after a week of driving, but I'm babying it until the 24th when it's set to get tuned.
Just using an ots map for now.
Also adding 1050 injectors, AEM fuel pump and Cobb regulator kit the same day.

Let us know how this goes 🙏. Is yours a 19+ STI? I think there still aren't any downpipes that work for the 19+ unfortunately.

 

[dbwillis]

Mines a 2020.
I'm not getting the cel that was expected (p0420 cat deficiency) I'm getting p0137, rear o2 circuit low voltage, tuner thinks the o2 is on the way out.
I actually just picked up a new o2 sensor yesterday to put in, hoping to put it in this am after the kids get up and off to school

 

[whatawhipur]

Mines a 2020.
I'm not getting the cel that was expected (p0420 cat deficiency) I'm getting p0137, rear o2 circuit low voltage, tuner thinks the o2 is on the way out.
I actually just picked up a new o2 sensor yesterday to put in, hoping to put it in this am after the kids get up and off to school

Nice, I have a 2021 and am wanting a downpipe but my tuner said there won't be any downpipes that work, aside from an off chance from the Cobb and grimmspeed ones. I was also going to do EWG, 1050s and aem 340 for e85

 

[dbwillis]

new o2 installed this AM, reset the ECU to start fresh. Also replaced the donut gasket as I noticed a small black soot mark on the top side of the DP...possibly a small leak from reusing the old one.
(I also have the AEM 340 and 1050s and the Cobb FP)

 

[whatawhipur]

new o2 installed this AM, reset the ECU to start fresh. Also replaced the donut gasket as I noticed a small black soot mark on the top side of the DP...possibly a small leak from reusing the old one.
(I also have the AEM 3340 and 1050s and the Cobb FP)

Would you mind sending a link to the downpipe you bought? I noticed Cobb doesn't have their downpipe on their website anymore for 15+ 😮‍💨

 

[dbwillis]

COBB GESI Catted 3 Inch Bellmouth Downpipe 2008-2014 WRX / 2008-2021 STI / 2005-2009 LGT MT / 2009-2013 FXT - Subimods.com