Removing Catalytic Converter - The Saab Link Forums

Go Back   The Saab Link Forums > Saab NG900 '94-'98 and 9-3 '99-'02 Forum > Performance Modifications for the NG900 / Old 9-3

Performance Modifications for the NG900 / Old 9-3 This forum contains PERFORMANCE related Q&A's for the NG900 and 9-3. This may also include suspension.

SaabLink.net is the premier Saab Forum on the internet. Registered Users do not see the above ads.
Reply
 
LinkBack Thread Tools
Old 06-23-2004, 06:06 AM   #1
Elder
 
rcmdesign's Avatar
 
Join Date: Dec 2003
Location: Erie, PA
Posts: 2,646
Removing Catalytic Converter

OK. I don't have emissions inspection anymore, so I was thinking about removing the cat and installing a straight pipe. But I have heard so many worries about the check engine light coming on after this modification. Is this true? I guess I got to get outside and check to see if I have two O2 sensors. But is there a way to hack the ECU to believing the cat is still there? Any suggestions would be greatly appreciated
__________________
Rob
Swedish Performance
1995 Saab 900S - 2.3L DOHC N/A 150K

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
rcmdesign is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Old 06-23-2004, 07:39 AM   #2
Moderator
Elder
 
Tweek's Turbos's Avatar
 
Join Date: Dec 2003
Location: Northern VA
Posts: 10,303
Send a message via AIM to Tweek's Turbos
Congradulations, You have a 95 Unless it started mid way thru, you should only have the 1.

Go out and buy yourself just the JT downpipe, no need for the cat. You wont regret it.
__________________
Quote:
Originally Posted by Delorean
- pretend you are watering delicate plants...
Quote:
Originally Posted by SAABseanSCANIA
can be prone to failure due to increased localized stresses in the hole penetrations
Tweek's Turbos is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote Quick reply to this message
Old 06-23-2004, 07:47 AM   #3
Elder
 
rcmdesign's Avatar
 
Join Date: Dec 2003
Location: Erie, PA
Posts: 2,646
I do not have a turbo model Do they offer a downpipe for the non-turbo cars?


Also, I have been calling some places to see if they can remove the Cat and replace it with a straight pipe and EVERYONE is turning me down, telling me it's a $2500 fine
__________________
Rob
Swedish Performance
1995 Saab 900S - 2.3L DOHC N/A 150K

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
rcmdesign is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote Quick reply to this message
 
Old 06-23-2004, 08:07 AM   #4
Flirting With TSL Addiction
 
Join Date: Feb 2004
Posts: 584
Quote:
Originally Posted by rcmdesign
I do not have a turbo model Do they offer a downpipe for the non-turbo cars?


Also, I have been calling some places to see if they can remove the Cat and replace it with a straight pipe and EVERYONE is turning me down, telling me it's a $2500 fine
It's probably a LOT more than that. It's illegal to even replace it with a non-OEM cat unless the car is over 5 years and 50k miles and you can demonstrate that it has failed - much less to replace it with a straight pipe.

Quick and dirty method is to unbolt it, hollow it out (crowbar) and put it back. You can do that yourself in a lazy afternoon. Or just order an aftermarket straight pipe and put it on yourself. Exhaust work is pretty straightforward.

Or, keep looking for a shop. Technically you can do anything you want to a vehicle that's not going to be used on public roads, so maybe you could find a shop willing to do the work if you told them it was a race car or something.
driver found is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote Quick reply to this message
Old 06-23-2004, 08:08 AM   #5
Elder
 
rcmdesign's Avatar
 
Join Date: Dec 2003
Location: Erie, PA
Posts: 2,646
Yeah but who enforces this fine? I don't get emissions inspection, so technically no one can report me for that when giving me state inspection...So what's the deal....
__________________
Rob
Swedish Performance
1995 Saab 900S - 2.3L DOHC N/A 150K

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
rcmdesign is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote Quick reply to this message
Old 06-23-2004, 08:12 AM   #6
Flirting With TSL Addiction
 
Join Date: Feb 2004
Posts: 584
Quote:
Originally Posted by rcmdesign
Yeah but who enforces this fine? I don't get emissions inspection, so technically no one can report me for that when giving me state inspection...So what's the deal....
If the authorities find out that the shop did it, the shop gets fined. The shop would probably care less if the fine was levied against you, but it's their own butts they are watching out for.

And yeah, it may seem unlikely, but I know of more than one shop that's been shut down around here because an undercover inspector was sitting in a car across the street watching them perform illegal actions.
driver found is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote Quick reply to this message
Old 06-23-2004, 08:16 AM   #7
Elder
 
rcmdesign's Avatar
 
Join Date: Dec 2003
Location: Erie, PA
Posts: 2,646
When you say "when the authorities find out" how would they ever find out...I mean do cops pull you over and check for your cat?


EDIT: I just noticed on Eric's site that it says: * Do not perform this modification if you have a naturally aspirated Saab. The decrease in backpressure will cause a decrease in performance and gas mileage. Anyone care to explain this?
__________________
Rob
Swedish Performance
1995 Saab 900S - 2.3L DOHC N/A 150K

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
rcmdesign is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote Quick reply to this message
Old 06-23-2004, 08:23 AM   #8
HNNLIC
Elder
 
Blaque's Avatar
 
Join Date: Oct 2003
Location: Washington, D.C. / Kansas City
Posts: 4,209
Send a message via ICQ to Blaque Send a message via AIM to Blaque Send a message via MSN to Blaque Send a message via Yahoo to Blaque
Actually, you could remove the cat with no problems, but getting a shop to do it is the hard part....which people have already explained so far.

Since I don't know of any aftermarkt exhausts for the N/A... you may want to find a Race shop, or Motorsports shop that can fab up an entire new exhaust system for you. They may not beable to construct a downpipe, but the downpipe back im sure they can do. While they are doing this and since it'll be at a motorsport or race shop, they may allow the system to be catless. Some shops may require you to sign a paper stating its strictly for race-use to cover their ass, but all in all they should be able to accomodate.

Either that, or just get a friend with a hack-saw and a welder, and buy a peice of straight piping.

If all else fails...just get a free flow cat. They're somewhat cheap, and aren't constricting...plus you'll still be legal.
__________________
Virtualization FTW. IT 4 Life.

“Brothers and sisters… and friends…and I see some enemies. In fact, I think we’d be fooling ourselves if we had an audience this large, and didn’t realize that there were.. some enemies present.” –Malcolm X


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Blaque is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote Quick reply to this message
Old 06-23-2004, 09:29 AM   #9
Flirting With TSL Addiction
 
Join Date: Feb 2004
Posts: 584
Quote:
Originally Posted by rcmdesign
When you say "when the authorities find out" how would they ever find out...I mean do cops pull you over and check for your cat?
See my above post - the shop is worried that they'll get fined, not that you'll get discovered at some later date. Inspectors do watch licensed shops, I've known a few that got shut down because they couldn't pay the fines levied against them.

Quote:
EDIT: I just noticed on Eric's site that it says: * Do not perform this modification if you have a naturally aspirated Saab. The decrease in backpressure will cause a decrease in performance and gas mileage. Anyone care to explain this?
Engines are designed to expect some back pressure. The mechanics are a bit complicated, but basically, the exhaust valves are sized and timed as if there will be back pressure on the exhaust gas. When you add aftermarket exhaust parts, they reduce the back pressure, and the engine will sometimes loose efficiency.
driver found is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote Quick reply to this message
Old 06-23-2004, 10:56 AM   #10
SAABeginner
 
Join Date: May 2004
Posts: 20
also, if you removed your cat and changed up the exhaust on a na car, it would be very very loud, considering the turbo muffles the engine some, while providing the needed backpressure. Without a turbo, the car would be much louder, as the cat also provides some muffling. Moral of the story? Keep your cat if youve got a NA car/

-Frank
roadkil34 is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote Quick reply to this message
Old 08-23-2013, 10:21 AM   #11
TSLMember
 
BalooBear86's Avatar
 
Join Date: Aug 2013
Location: Pittsburgh
Posts: 29
OMG I'm searching everywhere for a some info on this matter I was told that if i knock out the cat material it will open the exhaust up and eleminate back pressuer with a turbo thats good. I have a 2006 9-3 T8 i want to do this but what about the o2 sensors it will cause a code so how do i do this with out throwing a code?
BalooBear86 is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote Quick reply to this message
Old 08-23-2013, 10:39 AM   #12
 
mike saunders's Avatar
 
Join Date: Mar 2004
Location: Boston, MA
Posts: 6,468
Holy zombie thread!

Look at the date of the thread.
Look at the type of car it references.

You have a car with multiple cats, a different engine, and a different engine management system, so any advice given here wouldn't necessarily apply to you.

Multiple people here have told you your options, yet you seem insistent on de-catting your car....so just do it already! Take your exhaust apart, get a long section of rebar and punch out the ceramic catalytic matrix. Connect everything back together and get an O2 sensor simulator in place of the stock O2 sensor and hope for the best.

There. You're done.

But all you've done is fucked up your exhaust and not reduced backpressure by a huge amount because the most critical section of exhaust is actually the downpipe. Put in a bigger downpipe -- with a free-flowing cat -- and you'll reduce backpressure significantly.

And here's the kicker: the heat of the catalytic converter helps evacuate exhaust gasses, so the cat can actually help reduce backpressure.

Would you lookit there: I buried the lead.

Last edited by mike saunders; 08-23-2013 at 10:43 AM.
mike saunders is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote Quick reply to this message
Old 08-23-2013, 11:43 AM   #13
Live, eat, and sleep by TSL
 
Join Date: Aug 2010
Location: Glen Mills, PA (Phila)
Posts: 1,543
You should consider removing the entire exhaust system, because it creates a fair amount of backpressure.

Good luck!
BuHuSPG is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote Quick reply to this message
Old 08-26-2013, 10:03 AM   #14
TSLMember
 
BalooBear86's Avatar
 
Join Date: Aug 2013
Location: Pittsburgh
Posts: 29
Thanks I dont know why some one couldnt of just gave me a direct anwser like this the first time then i wouldnt of looked for another place to ask *shrugs* I'm just learning I didnt mean to piss any one off <_< Forums are sopost to be helpful and friendly all i do is get smart ass remarks for the most part
BalooBear86 is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote Quick reply to this message
Old 08-26-2013, 10:47 AM   #15
 
mike saunders's Avatar
 
Join Date: Mar 2004
Location: Boston, MA
Posts: 6,468
Dude, folks are actually trying to help you, but you're not helping yourself by limiting the scope of your question to your specific vehicle.

I'm pretty sure in one of your previous threads, people told you to just get a free-flowing cat and to use an O2 simulator or a spark plug extender, and that the effectiveness of these on T8 is still an open book.
mike saunders is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the The Saab Link Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Vehicle Info.
Enter your vehicle information (year, model, mods)
Insurance
Please select your insurance company (Optional)

Log-in


Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -8. The time now is 08:40 PM.


Powered by vBulletin® Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Friendly URLs by vBSEO 3.5.2
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
All content is copyright © The Saab Link and it's original authors.


 

Garage Plus vBulletin Plugins by Drive Thru Online, Inc.