what else beside upgrade upp/dp

after 120+k milages, i decided to stage 2 it. i found some suggest to replace those O2 sensors as well, thats kinda make sense to me since they are already 120+k old, and i have to install new up/dp anyway..

then i searched the maintenance guide HERE, unfortunately its no longer working. but i found someone posted a diagram it shown the sensor that attached to the uppipe is temperature sensor. O2 sensors are one on the exhaust manifold and the second one sit "behind" the dp.

so i'm confused now. shall i have a new temperature sensor too? but i couldnt find any info..

thanks

There's only two sensors in the exhaust. Front and rear o2. The front one also reads temperature to determine, I believe, something with the idle to make sure the cat in the up pipe stays healthy or something along those lines.

The front one measures narrow band afr and is important, you don't care about the temp part of it because you should be running a catless up as is.

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Your, Spec B doesn't have the egt probe in the up pipe.

that's more confused now, coz i saw Invidia up (for 2005-2009 legacy) has a bung but none on the Cobb's.

There's only two sensors in the exhaust. Front and rear o2. The front one also reads temperature to determine, I believe, something with the idle to make sure the cat in the up pipe stays healthy or something along those lines.

meaning i 'llneed both front and rear O2?

The front one measures narrow band afr and is important, you don't care about the temp part of it because you should be running a catless up as is.

and yes, most ppl suggested catless UP is more safe for the turbo and it's on my buying list

If you're going to replace them then yea.

It's sort of a weird grey area. You can delete both. The rear just basically checks the rear cat. You need to have the ecu measure afr for closed loop maf scaling. But I guess you wouldn't need that if you did a tune that bypassed the maf.

The short answer is get an up pipe with the bung and replace it with a new oem sensor (they aren't cheap but aftermarket ones tend to have issues) and call it a day. The in and out of do you need one is too complicated imo.

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You don't need to replace "your" up pipe, OEM is the best for long life.

All 4th Gen's can use the same part. Not that you need to replace your 09 up pipe.

My 09 Spec B has its OEM up pipe.

Doh! Didn't check the car earlier. Yea no need to change that, which in that case just leave the o2 sensor in there. Chances are you won't get it out anyway.

Only reason I'll change mine in my 08 is if something goes bad or my uppipe finally rusts through. You won't see any appreciable difference from a change to that up pipe. And for the cost, replacing o2 sensors early is silly.

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My 09 Spec B has its OEM up pipe.

even stage 2 and up?

07 Legacy Gt I just picked up two weeks ago.

220k, but motor has be resealed 80k ago. Everything else is still oem, kept oem catless uppipe alone. Went to stage two with no issues.

However, look over your tmic. Mine was separated and causing a leak, but replaced with a process west one and going strong!

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even stage 2 and up?

Yes.

FWIW, both my cars have the Grimmspeed TMIC for reliability and ease of install.

I also run a K&N air filter, lightly oiled on both cars.

With a great tune these cars are great fun.

However, look over your tmic. Mine was separated and causing a leak, but replaced with a process west one and going strong!

 

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thought about the TMIC too since i'm living at south of texas with sometime three digits summer, but a friend of mine with 06 STi said havent seen any heatsoak with his stock TMIC...

I also run a K&N air filter, lightly oiled on both cars. With a great tune these cars are great fun.

First, i checked Cobb website and found their map wouldnt support anything mods beyond turbo back unless protune.

plus, i had a miata with jackson racing intake, and the panel(K&N?) gave me lot of troubles. trust me, i really treated (clean/oil?) it well but it just didn't last long.

oh, by the way, do i need any new O2 sensor on the midpipe as well? since i'm also going to change the exhaust and i'll need to unplug the old one anyway.

If remove the old sensor, do i really need socket or any simple tools instead, so i won't break anything?

thanks

The Perrin Panel filter I installed in my 2005 Wagon (purchase date June 28 2004) back in Aug 2004 lasted until around 2014 or so when it began to look old. The car didn't have any issue from the panel filter. The car was on Cobb AP V1 early Dec 2004 when it first came out, car had 8,000 miles in it.

My Spec B had the K&N when I bought it March 2011, car had 22,000 miles, it's build date was Jun 6 2008, it came with Cobb AP V2.

Both cars still have the OEM air intake box, less silencers under the box.

Just saying.

I agree heat soak is not a real issue unless your to OCD. I will say, on the hot summer day's sitting in traffic, I will be aware of not giving it full boost until I've driven in clean air for a short distance.

Better safe than sorry.

But very few of us have gone to a fmic.

oh, by the way, do i need any new O2 sensor on the midpipe as well? since i'm also going to change the exhaust and i'll need to unplug the old one anyway.

 

If remove the old sensor, do i really need socket or any simple tools instead, so i won't break anything?

 

 

thanks

The rear O2 is in the downpipe.

I suggest you get the O2 socket, its only a few $$'s and put a screw type hose clamp around it to keep it from spreading as you try to remove the sensor...that's after you've sprayed the sensor with PB Blaster or something better. Give the fluid a short time to work...

Put a small dab of anti-seize compound on the threads before you install the O2 sensor. I put anti-seize on all threads before I install anything on these cars, even the lug nuts.

Better safe than sorry.

 

But very few of us have gone to a fmic.

Absolutely agree my friend, better safe than sorry!!

Since 20+yrs ago i started playing go-kart, and tracks. All mods are became self-enjoyment. yea.. sometime i WOT for 2, 3 secs on empty traffic but thats it. .. So, FMIC is kinda too aggressive to my taste and power is really minor specially track race.

hey, thanks for you quick replies Max

The rear O2 is in the downpipe.

 

.. sprayed the sensor with PB Blaster or something better. Give the fluid a short time to work...

 

Put a small dab of anti-seize compound on the threads before you install the O2 sensor. I put anti-seize on all threads before I install anything on these cars, even the lug nuts.

Oh thanks for your reminder .. totally forgot this trick!

The rear O2 is in the downpipe.

 

is this the one?

thanks

That might be the rear.

The front is Denzo 234-9120, I have it written in my note book. My rear is disabled by my Tuner as far as I know.

Check JmP's stick up top about various parts...I know the Front is in that thread.

That might be the rear.

 

The front is Denzo 234-9120, I have it written in my note book. My rear is disabled by my Tuner as far as I know.

Check JmP's stick up top about various parts...I know the Front is in that thread.

thought i just need a rear since i'm going to remove the old dp right? or do i need to replace both front and the rear sensors?

Your front should be fine, that was just for future reference.

If there is nothing wrong with your rear, just re-use it.

Your front should be fine, that was just for future reference.

 

If there is nothing wrong with your rear, just re-use it.

got it, thanks Max