3" straight exhaust?'s

[skapegoat]

I'm thinking about putting in a straight 3" turbo back exhaust. Just wondering how it will affect the ecu. Will it throw a light if I put the o2 in the same place without a cat? Will there be enough back pressure or do turbo cars not need back pressure? What other problems will arise?

 

[architechnik]

You'll throw a code for the rear O2 sensor and you'll have a wider power band and higher peak power. Nothing else bad would happen other than it being a lot louder.

 

[skapegoat]

It seems like a few years ago I saw something like a dummy o2 sensor that put out a good exhaust signal. Does that exist and what is it called?

 

[undefined0000]

The turbo is fundamentally the back pressure. The easier the exhaust can get out, the better. I LOVE my 3" exhaust, really puts you off to the side compared to the inline 4 cylinders. The high rpm "fart" isn't there and it SCREAMS. If you're feeling adventurous, run open down-pipe for a little and drive around. Sounds delicious.

 

[skapegoat]

Back in the day I had a 2.5" glass pack right off the header out the side of the front bumper. Sounded pretty mean but this tsi has the intercooler piping in the way.

 

[WRXkiller92]

STM has a little bung you can screw onto your O2 sensor and it won't throw a check engine light, idk how it works but it's pretty spiffy.

 

[genegoesfast]

It's pretty much just a spark plug non fouler that pulls the o2 sensor out of the exhaust stream a bit to trick into thinking there's a cat still present.

 

[NWHTanK]

This is interesting topic. I'm doin a srt swap in my eclipse and I have a lot of the srt stuff that I've kept. The car didn't have a cat but had a 3 inch down pipe with a spacer tube for the o2 sensor? I didn't build the srt-4 but bought it for parts. So I'm guessing that this is the fowller or a weird kind of spacer.

 

[NWHTanK]

I took out the o2 sensor? And this is what it looks like.

 

[skapegoat]

How important is the flex pipe. I was just going to make the entire thing one solid piece of 3"

 

[NWHTanK]

That is a srt piece. But the Dsm have them also. The engine and trans move. So to keeps the pipe from hitting the under side of the car.

 

[NWHTanK]

It also keeps it from cracking exhaust parts because of engine torque.

 

[NWHTanK]

The one on top is dsm.

 

[obsidian]

look up how to do a spark plug anti fouler o2 sensor fix. save your time and money

 

[crash89]

Doing a solid pipe would only be ok with solid engine mounts.. Like said above, engine torque will put pressure on the exhaust and will eventually crack something. For your question about it throwing a code, yes. Without a Cat the rear o2 will not be reading what its supposed to. So unless you have link you will throw a code..

Heres my 3'' straight pipe exhaust. I know its not pretty I had to piece it together with stainless we had laying around.

Off the turbine
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Vs a stock exhaust
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[skapegoat]

This morning I looked it over closely and wound up going with a 2.5" straight off the flex pipe. Even with the a o2 sensor socket I managed to snap it off. Now I need to figure out where it unplugs. I'm not real excited about how it sounds. Too popy for me.

 

[dougiefresh]

just make sure you still have all the sensors