Exhaust alternatives for WRX STI MY03
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Exhaust alternatives for WRX STI MY03
First of all, i'm very sorry if this is a FAQ.
I am planning to change my exhaust on my sti my03. I had a my00 Impreza GT before (the 2000 Turbo in the UK) and it was never a problem to use a Magnex DP and a better backbox on that one, even before i went for a Tek-remap.
But i understand that the euro spec. wrx sti have some problems with this (running lean), so i will have to invest in a better fuel-pump when changing the exhaust. As i understand it, the sti has 3 cats and that there is a problem with the CEL light coming on when one of them is replaced (the front one i presume).
In your opinion, what would be the best option for the STI:
- changing the downpipe and backbox and keep 2 cats?
- keeping the downpipe and let the rest be a straight-through system?
Which would be "safest" and still provide more "grunt"?
Speaking of backboxes, which one will be best for "opening it up" while still not doing to much noise?
Kind regards
Daniel (from the land of the Turnips)
I am planning to change my exhaust on my sti my03. I had a my00 Impreza GT before (the 2000 Turbo in the UK) and it was never a problem to use a Magnex DP and a better backbox on that one, even before i went for a Tek-remap.
But i understand that the euro spec. wrx sti have some problems with this (running lean), so i will have to invest in a better fuel-pump when changing the exhaust. As i understand it, the sti has 3 cats and that there is a problem with the CEL light coming on when one of them is replaced (the front one i presume).
In your opinion, what would be the best option for the STI:
- changing the downpipe and backbox and keep 2 cats?
- keeping the downpipe and let the rest be a straight-through system?
Which would be "safest" and still provide more "grunt"?
Speaking of backboxes, which one will be best for "opening it up" while still not doing to much noise?
Kind regards
Daniel (from the land of the Turnips)
Scooby Regular
Joined: Jun 2004
Posts: 111
Likes: 0
Originally Posted by my03
First of all, i'm very sorry if this is a FAQ.
I am planning to change my exhaust on my sti my03. I had a my00 Impreza GT before (the 2000 Turbo in the UK) and it was never a problem to use a Magnex DP and a better backbox on that one, even before i went for a Tek-remap.
But i understand that the euro spec. wrx sti have some problems with this (running lean), so i will have to invest in a better fuel-pump when changing the exhaust. As i understand it, the sti has 3 cats and that there is a problem with the CEL light coming on when one of them is replaced (the front one i presume).
In your opinion, what would be the best option for the STI:
- changing the downpipe and backbox and keep 2 cats?
- keeping the downpipe and let the rest be a straight-through system?
Which would be "safest" and still provide more "grunt"?
Speaking of backboxes, which one will be best for "opening it up" while still not doing to much noise?
Kind regards
Daniel (from the land of the Turnips)
I am planning to change my exhaust on my sti my03. I had a my00 Impreza GT before (the 2000 Turbo in the UK) and it was never a problem to use a Magnex DP and a better backbox on that one, even before i went for a Tek-remap.
But i understand that the euro spec. wrx sti have some problems with this (running lean), so i will have to invest in a better fuel-pump when changing the exhaust. As i understand it, the sti has 3 cats and that there is a problem with the CEL light coming on when one of them is replaced (the front one i presume).
In your opinion, what would be the best option for the STI:
- changing the downpipe and backbox and keep 2 cats?
- keeping the downpipe and let the rest be a straight-through system?
Which would be "safest" and still provide more "grunt"?
Speaking of backboxes, which one will be best for "opening it up" while still not doing to much noise?
Kind regards
Daniel (from the land of the Turnips)
Scooby Regular
Joined: Dec 1998
Posts: 1,687
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Hi Daniel! 
I had the exact same problem on my STi, I took the downpipe and centre cat out of the system, and it did indeed run lean.
I would consider just taking out the centre cat, and leaving the downpipe in place.
Failing that I would recommend that you upgrade the fuel pump and/or obtain a remap.
If you need any help please let me know, I'd be more than happy to help, and we have just put up the new Scoobysport systems on our site for you to have a look at, we also have a cracking offer on Blitz Nur Spec R systems for the MY01 onwards models!
Jamie
www.j-w-racing.co.uk
I had the exact same problem on my STi, I took the downpipe and centre cat out of the system, and it did indeed run lean.
I would consider just taking out the centre cat, and leaving the downpipe in place.
Failing that I would recommend that you upgrade the fuel pump and/or obtain a remap.
If you need any help please let me know, I'd be more than happy to help, and we have just put up the new Scoobysport systems on our site for you to have a look at, we also have a cracking offer on Blitz Nur Spec R systems for the MY01 onwards models!
Jamie
www.j-w-racing.co.uk
Thread Starter
Scooby Newbie
Joined: Mar 2004
Posts: 13
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good pointers
Hi Jamie,
Thanks for your good advice. One learns something new every day :-)
I guess that Walbro 255 and a remap will be necessary when i'll start to exchange parts....
Checked out the j-w racing store/site and you do have some very interesting things for sale. Sooner or later i will pay our EcuTek mappers a visit again and before then i will most probably pay your site a visit looking to order a downpipe and/or middle-section. One question Jamie: do you sell downpipes with metallic cats or are they all straight through?
After browsing around quite a bit i decided to go for a Ninja exhaust. Don't like it when they sound "too" much so this one will be a good compromise i think.
Kind regards
Daniel
Thanks for your good advice. One learns something new every day :-)
I guess that Walbro 255 and a remap will be necessary when i'll start to exchange parts....
Checked out the j-w racing store/site and you do have some very interesting things for sale. Sooner or later i will pay our EcuTek mappers a visit again and before then i will most probably pay your site a visit looking to order a downpipe and/or middle-section. One question Jamie: do you sell downpipes with metallic cats or are they all straight through?
After browsing around quite a bit i decided to go for a Ninja exhaust. Don't like it when they sound "too" much so this one will be a good compromise i think.
Kind regards
Daniel
Originally Posted by Jamie Whitfield
Hi Daniel!
I had the exact same problem on my STi, I took the downpipe and centre cat out of the system, and it did indeed run lean.
I would consider just taking out the centre cat, and leaving the downpipe in place.
Failing that I would recommend that you upgrade the fuel pump and/or obtain a remap.
If you need any help please let me know, I'd be more than happy to help, and we have just put up the new Scoobysport systems on our site for you to have a look at, we also have a cracking offer on Blitz Nur Spec R systems for the MY01 onwards models!
Jamie
www.j-w-racing.co.uk
I had the exact same problem on my STi, I took the downpipe and centre cat out of the system, and it did indeed run lean.
I would consider just taking out the centre cat, and leaving the downpipe in place.
Failing that I would recommend that you upgrade the fuel pump and/or obtain a remap.
If you need any help please let me know, I'd be more than happy to help, and we have just put up the new Scoobysport systems on our site for you to have a look at, we also have a cracking offer on Blitz Nur Spec R systems for the MY01 onwards models!
Jamie
www.j-w-racing.co.uk
Last edited by my03; Jul 8, 2004 at 10:06 PM.
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