JDL Header & Exhaust System Development

[xxscaxx]

Originally Posted by JDLAutoDesign

Yes we have it scheduled just really busy with getting the car ready


Sent from my iPhone using Tapatalk

yeah understandable. Your twinscroll kit looks insane. I might have to sell a kidney

Thanks for responding! (and sorry for being a PITA )

[JDLAutoDesign]

Got lots of stainless in today. EL & a few UEL headers

[ATL BRZ]

Originally Posted by JDLAutoDesign

Got lots of stainless in today. EL & a few UEL headers

Any fueling or AFR issues with the secondary O2 sensor spacer on the catless headers running on a STOCK ecu tune? I noticed in the pics of the EL header that there's a spacer/spark plug anti fouler on the second O2 sensor, presumably to avoid getting a CEL.

Check this out: http://forums.nasioc.com/forums/show....php?t=2234058

OK, this one is coming back again because a couple of vendors offer what they call "O2 Sensor Spacers" that they incorrectly list as compatible with 2005+ Subarus. I'm getting PMs about these on a pretty regular basis.

They're also available as spark plug anti-foulers or as little extension tubes welded on to the pipe.

Regardless of what they're called, what they do is to move the O2 sensor physically farther away from the main exhaust flow in hopes of tricking the ECU into not throwing the P0420 DTC when you run headers, a HFC, or a trackpipe. While on some cars they do actually prevent the P0420 DTC from being thrown, they cause fueling problems on all cars 2005 and newer. In 2005, Subaru switched to an ECU that uses the input from the rear O2 sensor to affect fueling in addition to simply monitoring the cat (as in 2004 and older cars). If you remove the rear O2 sensor entirely, mount it somewhere that isn't in the exhaust at all (don't laugh, I've seen it done), or even just move it out of the main exhaust flow, you'll develop strange fueling errors as the ECU tries to make the rear O2 see what it's programmed to achieve. The result of this is slightly worse fuel economy, a worse idle, and generally increased difficulty in getting the car tuned to a good state.

Summary: DO NOT USE O2 SENSOR SPACERS OR SPARK PLUG ANTI-FOULERS ON 2005 OR NEWER SUBARUS.


Also, it's worth noting that you can't use electronic "MIL Eliminators" like the ones from Pony Express on 2005 and newer Subarus either. Your only solution to getting a P0420 DTC on the newer cars is to disable it in the tune.

Makes me nervous about using one with the stock tune.

[JDLAutoDesign]

We ran ours on the stock ECU no tune whatsoever with no fueling issues at all. We have air fuel graphs to show as well as graphs of our AF to show it with the sensor completely unplugged.

We also stated that if this is an issue we would move the secondary bung behind the catted front pipe. Whatever is most comfortable for the customer is what we wil do

[ATL BRZ]

Originally Posted by JDLAutoDesign

We ran ours on the stock ECU no tune whatsoever with no fueling issues at all. We have air fuel graphs to show as well as graphs of our AF to show it with the sensor completely unplugged.

We also stated that if this is an issue we would move the secondary bung behind the catted front pipe. Whatever is most comfortable for the customer is what we wil do

Good info, thanks! This needs to be in the OP of all the catless header threads!

[JDLAutoDesign]

Im going to take a few pics to show the procedure and leave the option up to the customer. Since we are EMS we arent running it at all any more

[xxscaxx]

Friday bump

[HRTROB]

Originally Posted by JDLAutoDesign

We ran ours on the stock ECU no tune whatsoever with no fueling issues at all. We have air fuel graphs to show as well as graphs of our AF to show it with the sensor completely unplugged.

We also stated that if this is an issue we would move the secondary bung behind the catted front pipe. Whatever is most comfortable for the customer is what we wil do

So you're saying the secondary o2 sensor does nothing more than check for the quality of air after the cat, correct? AFR stayed the same with the secondary o2 sensor unplugged?

[JDLAutoDesign]

The wideband O2 sensor for the Dyno was in the spot where the secondary normally goes.

[xxscaxx]

Originally Posted by JDLAutoDesign

Got lots of stainless in today. EL & a few UEL headers

[Tansey86]

Originally Posted by JDLAutoDesign

The wideband O2 sensor for the Dyno was in the spot where the secondary normally goes.

When does the catback get released? Excited to see what the single looks like the from the back.

[Simmons]

Originally Posted by Tansey86

When does the catback get released? Excited to see what the single looks like the from the back.

And what it weighs.

Simmons

[Tansey86]

Originally Posted by Simmons

And what it weighs.

Simmons

I heard the entire system netted them over 40 lbs in weight loss. Pretty impressive.

[ngabdala]

UEL ETA? Bump