C5 Tech Corvette Tech/Performance: LS1 Corvette Technical Info, Internal Engine, External Engine, Tech Topics, Basic Tech, Maintenance, How to Remove & Replace
Sponsored by:
Sponsored by:

High Flow Cats And Codes

Thread Tools
 
Search this Thread
 
Old Dec 30, 2007 | 03:25 AM
  #1  
03redzo6's Avatar
03redzo6
Thread Starter
Pro
15 Year Member
 
Joined: Feb 2007
Posts: 621
Likes: 2
From: La Quinta Ca
Default High Flow Cats And Codes

i bought a set of magnaflow high flow cats and now i just need to know if i install them will codes pop up and if so should i buy some 02 sims or will i be ok. thanks, albert.
Reply
Old Dec 30, 2007 | 07:14 AM
  #2  
trussme's Avatar
trussme
Burning Brakes
 
Joined: Jan 2006
Posts: 1,170
Likes: 27
From: Magnolia Greens NC
Default

Yes, Codes P0420 & P0430 will soon trigger your CEL in the DTC...so, Your best bet is to have your 2 rear (Bank 1 & 2) 02 sensors turned OFF...by a Tuner. "02 sims" will work initially, but are a "band aid", and most eventually fail...

Last edited by trussme; Dec 30, 2007 at 07:18 AM.
Reply
Old Dec 30, 2007 | 08:09 AM
  #3  
AU N EGL's Avatar
AU N EGL
Team Owner
10 Year Member
 
Joined: Sep 2003
Posts: 43,084
Likes: 33
From: Raleigh / Rolesville NC
Default

Random Tech High flow cats here for over three years. No codes what so ever.

Then again my car gets dyno tuned each winter too. Might be the tuner just takes them out
Reply
Old Dec 30, 2007 | 09:15 AM
  #4  
Blue Lightening's Avatar
Blue Lightening
Burning Brakes
20 Year Member
Conversation Starter
All Eyes On Me
 
Joined: May 2003
Posts: 850
Likes: 0
From: Green Lane Pennsylvania
Default

Originally Posted by AU N EGL
Random Tech High flow cats here for over three years. No codes what so ever.
Same here had Random Tech High Flow cats since 2003 no cat codes ever.
Reply
Old Dec 30, 2007 | 10:11 AM
  #5  
whiteC5TN's Avatar
whiteC5TN
Heel & Toe
 
Joined: Aug 2007
Posts: 24
Likes: 0
From: Oak Ridge Tennessee
Default

i removed my cats completely, and i havent seen any codes at all! i guess im just lucky
Reply
Old Dec 30, 2007 | 03:29 PM
  #6  
03redzo6's Avatar
03redzo6
Thread Starter
Pro
15 Year Member
 
Joined: Feb 2007
Posts: 621
Likes: 2
From: La Quinta Ca
Default

do you guys know if there is a how to for turning off the o2 sensors with ls1 edit. thanks, albert.
Reply
Old Dec 30, 2007 | 05:08 PM
  #7  
LS1 REDBIRD's Avatar
LS1 REDBIRD
Racer
20 Year Member
Conversation Starter
All Eyes On Me
 
Joined: Apr 2006
Posts: 405
Likes: 3
From: FRESNO CA
Default

Will it still pass emissions tuning rear O2's off?
Reply
Old Dec 30, 2007 | 07:52 PM
  #8  
03redzo6's Avatar
03redzo6
Thread Starter
Pro
15 Year Member
 
Joined: Feb 2007
Posts: 621
Likes: 2
From: La Quinta Ca
Default

Originally Posted by LS1 REDBIRD
Will it still pass emissions tuning rear O2's off?
i think if you replace your cats with high flow cats it will not pass smog atleast the inspection part.


does anyone know how to turn off the o2 sensors with ls1 edit, thanks.
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

 Michael S. Palmer
story-1

Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

 Joe Kucinski
story-2

150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

 Joe Kucinski
story-3

8 Coolest Corvette Pace Cars (and Replicas) of All Time

 Verdad Gallardo
story-4

Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

 Joe Kucinski
story-5

Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

 Verdad Gallardo
story-6

Top 10 Corvettes Coming to Mecum Indy 2026!

 Brett Foote
story-7

Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

 Michael S. Palmer
story-8

10 Revolutionary 'Corvette Firsts' Most People Don't Know

 Joe Kucinski
story-9

5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

 Michael S. Palmer
Old Dec 31, 2007 | 10:34 AM
  #9  
corvettejoe98's Avatar
corvettejoe98
Racer
 
Joined: May 2006
Posts: 410
Likes: 1
From: NJ
Default

ok you take your sensors off it wont pass the smog test unless you beat the hell out of your car right before you get it inspected to get it as hot as possible (reduces emissions), also you cant have any codes popping up or you fail, happened to my dad on his 98 vert and 01 Z they failed him on both of them. Anyway though if you get a handheld tuner i know that you can disable the O2 sensors, You should buy a handheld tuner cause they are always good to have about 300 for one, and then when you get the time or money run over and have your car dynotuned but disabling the O2 sensors with a handheld will get rid of the code.
Reply
Old Dec 31, 2007 | 10:49 AM
  #10  
EStreeter's Avatar
EStreeter
Burning Brakes
 
Joined: Feb 2005
Posts: 752
Likes: 1
From: Tulsa OK
Default

Originally Posted by 03redzo6
i think if you replace your cats with high flow cats it will not pass smog atleast the inspection part.


does anyone know how to turn off the o2 sensors with ls1 edit, thanks.
I get codes from the downstream O2 sensors and just reset the DIC to remove them when they pop up. I have hi-flow metal matrix cats and the codes come back now and then. The downstream O2s just measure the cat efficiency and I don't think they cause any pcm changes so the codes don't really mean anything in terms of engine performance like the upstream O2 sensors do.

It takes a few seconds to reset the DIC.
Reply
Old Dec 31, 2007 | 07:23 PM
  #11  
Speed Hound's Avatar
0Speed Hound
Former Vendor
 
Joined: Jan 2006
Posts: 698
Likes: 0
From: Social Circle Georgia
Default

For everyone that is not an 04, you may get a code saying the cats are not doing their job shortly after installing headers. You may have to clear this code once or twice. If it comes up a third time, go have them turned off. Basically the PCM is seeing a change it does not like. By clearing the code the first time, you're telling it to shut up and accept it. Some PCMs are stubborn and need a second shut up. I've never had one come up a third time.

For you guys with 04s, Random Technology makes an inline adapter that you plug into the rear O2 circuit that keeps the car from through the codes. This does not disable the rear O2s in any way, shape, or form. This year was very temperamental for whatever reason and turning the codes off or using these adapters are the only ways to keep the light off. The adapters are like $25 each I want to say. Any Random dealer can get them. Contact me or your preferred dealer if you're having issues.

rear O2s only measure catalyst efficiency. They have no effect on performance.
Reply

Get notified of new replies

To High Flow Cats And Codes





All times are GMT -4. The time now is 05:41 AM.

story-0
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

Slideshow: How to Protect A Convertible Top: 10 DOs & DON'Ts

By Michael S. Palmer | 2026-04-03 00:00:00


VIEW MORE
story-1
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

Slideshow: The 10 most explosive Corvettes ever built based on power-to-weight ratio.

By Joe Kucinski | 2026-05-20 07:23:03


VIEW MORE
story-2
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-3
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE
story-4
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

Slideshow: Ranking the top 10 Corvette engines by torque output.

By Joe Kucinski | 2026-05-05 11:58:09


VIEW MORE
story-5
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

Slideshow: A Corvette pace car nearly matching IndyCar speeds sounds exaggerated, until you look at the numbers.

By Verdad Gallardo | 2026-05-04 20:03:36


VIEW MORE
story-6
Top 10 Corvettes Coming to Mecum Indy 2026!

Among a rather large group of them.

By Brett Foote | 2026-05-04 13:56:44


VIEW MORE
story-7
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

Slideshow: the top 10 things Corvette owners want in the C9 Corvette

By Michael S. Palmer | 2026-04-30 12:41:15


VIEW MORE
story-8
10 Revolutionary 'Corvette Firsts' Most People Don't Know

Slideshow: 10 Important Corvette 'firsts' that every fan should know.

By Joe Kucinski | 2026-04-29 17:02:16


VIEW MORE
story-9
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

Slideshow: Should you buy a 2020-2026 Corvette or wait for 2027?

By Michael S. Palmer | 2026-04-22 10:08:58


VIEW MORE