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View Poll Results: What is better for performance
OEM Exhaust With catalyc converter
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OEM Exhaust Without catalyc converter
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S4 B5 with or without catalyc converter

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Old Nov 30, 2008 | 06:53 AM
  #1  
speedys4's Avatar
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Default S4 B5 with or without catalyc converter

What is better for engine.... i have only two o2 sensors (lambda) and two EGTs.
Model 99 before facelift.


the engine can function properly without a catalyst? Or it is very bad for engine. Without modification of ecu.

please help...
 
Old Nov 30, 2008 | 09:40 AM
  #2  
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If you have no post converter oxygen sensors, I would remove them. The less restriction on a turbo motor, the better.

Mike
 
Old Nov 30, 2008 | 12:00 PM
  #3  
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From: St. Charles MO, on youtube: GERMANPOWER90.
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Yeah, if there isnt any 02 sensors behind the cats, I would remove them. Less restriction, less heat, more power!
 
Old Nov 30, 2008 | 01:13 PM
  #4  
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i removed my precats.. and no turbo lag.. and engine revs freely till redline.. feels just way more responsive... and probably gained 10 to 15 bhp.. my car is chipped as well..
 
Old Nov 30, 2008 | 01:28 PM
  #5  
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ok, because if I removed them..i have only problems, maybe is it only problem with o2 sensor, which is bad...and my car isnt drive good at low rpm
 
Old Dec 4, 2008 | 12:06 PM
  #6  
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stock exhaust without CATs
http://www.youtube.com/watch?v=P9ESD4FVP9Y
 
Old Dec 4, 2008 | 03:18 PM
  #7  
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Sounds good.

I like this video i wish i had roads like that to drive on

http://www.youtube.com/watch?v=2yH_J...eature=related
 
Old Dec 4, 2008 | 04:01 PM
  #8  
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From: St. Charles MO, on youtube: GERMANPOWER90.
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sounds nice!
 
Old Dec 5, 2008 | 03:23 AM
  #9  
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I like this sound too....

I solved my problem with shaking of engine yesterday.... and i am very lucky
 
Old Dec 5, 2008 | 08:12 AM
  #10  
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damn that sounds great
 



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