Generation III External Engine LS1 | LS6 | Bolt-Ons | Intakes | Exhaust | Ignition | Accessories
Sponsored by:
Sponsored by:

ses exhaust question

Thread Tools
 
Search this Thread
 
Old Jul 8, 2007 | 09:40 PM
  #1  
px33transam's Avatar
Thread Starter
Staging Lane
 
Joined: Jan 2006
Posts: 73
Likes: 1
From: Rices Landing PA
Default ses exhaust question

I have a 2000 trans am LS1 with just a few mods. Today when I was driving my car (98 degrees 80% humidity) the ses light came on and my car started running like crap. I pulled into the local Advance auto and they scanned my codes and they said both rear O2 sensors were bad and 1 Cat was bad. Two questions one would the cat being bad make my car fall on its face and run bad and if the O2 sensors are both bad how does it know the converter is bad? Isn't the O2 sensor what moniters the cats? Oh one more question can I just gut the cats if they are bad and buy O2 sims to solve both problems until I can save for my headers and Y-pipe? Thanks in advance
Reply
Old Jul 9, 2007 | 03:59 PM
  #2  
68chevypu's Avatar
Launching!
iTrader: (18)
 
Joined: Aug 2005
Posts: 203
Likes: 0
From: Stockton CA
Default

yeah the rear o2 sensors only monitor the cats. If they went bad it wouldnt effect you car. Nor would a bad cat. I'm not sure how the PCM would know that the cat is bad. You could gut the cats and add o2 sims without a problem. I would suggest getting the actual codes that you are throwing. Then research from there.

If it was running like crap maybe one of the plug wires was arching. Have you started/driven it since the problem? Im not sure if an arching wire would cause some of the other problems you have. Maybe all that unburnt fuel was too much for the cat and some slipped through causeing the sensor to show a bad cat?

Let us know what you find.
Reply
Old Jul 9, 2007 | 04:39 PM
  #3  
2001NBMZ28's Avatar
TECH Senior Member
 
Joined: Dec 2001
Posts: 5,399
Likes: 3
From: Jacksonville, FL
Default

Do you have the actual codes? I wouldn't trust those guys just saying 02s are bad. BTW stock cats are covered under warranty by GM now for 10yrs/120K on the 00-02 F cars.
Reply
Old Jul 9, 2007 | 07:23 PM
  #4  
px33transam's Avatar
Thread Starter
Staging Lane
 
Joined: Jan 2006
Posts: 73
Likes: 1
From: Rices Landing PA
Default

Hey thanks for the info guys. I drove my car to work today and it ran OK. I'm a little embarassed to tell ya what I think I discovered the problem to be but here goes. My buddy at work said sounds like you got bad gas.....then I started thinking. It started running better after I filled it up this morning on my way to work so when I got home I checked the directions on a bottle of octane boost/ fuel injector cleaner I put in when the car had a 1/4 tank of gas and it said mix with 25 gal of gas. Oh by the way ses light is out now also. I am calling the garage tomorrow to have them check codes and ask about that warranty info. Sorry to waste you guy's valuable time on my stupid mistake but I do appreciate the info
Reply
Old Jul 9, 2007 | 07:30 PM
  #5  
68chevypu's Avatar
Launching!
iTrader: (18)
 
Joined: Aug 2005
Posts: 203
Likes: 0
From: Stockton CA
Default

Originally Posted by 2001NBMZ28
Do you have the actual codes? I wouldn't trust those guys just saying 02s are bad. BTW stock cats are covered under warranty by GM now for 10yrs/120K on the 00-02 F cars.

really? its that high now. damn last I heard it was like 8/80 but thats cool
Reply
Old Jul 9, 2007 | 07:31 PM
  #6  
68chevypu's Avatar
Launching!
iTrader: (18)
 
Joined: Aug 2005
Posts: 203
Likes: 0
From: Stockton CA
Default

Originally Posted by px33transam
Hey thanks for the info guys. I drove my car to work today and it ran OK. I'm a little embarassed to tell ya what I think I discovered the problem to be but here goes. My buddy at work said sounds like you got bad gas.....then I started thinking. It started running better after I filled it up this morning on my way to work so when I got home I checked the directions on a bottle of octane boost/ fuel injector cleaner I put in when the car had a 1/4 tank of gas and it said mix with 25 gal of gas. Oh by the way ses light is out now also. I am calling the garage tomorrow to have them check codes and ask about that warranty info. Sorry to waste you guy's valuable time on my stupid mistake but I do appreciate the info

no prob. You will want to change your fuel filter now though. Most injector cleaners have solvents that strip **** of the inside of the tank. The filter should have caught it all. Just change it out pretty soon.
Reply
Old Jul 9, 2007 | 08:24 PM
  #7  
px33transam's Avatar
Thread Starter
Staging Lane
 
Joined: Jan 2006
Posts: 73
Likes: 1
From: Rices Landing PA
Default

Never thought of changing filter but good point I'll pick up one tomorrow. Thanks
Reply
Old Jul 9, 2007 | 10:13 PM
  #8  
5_02ls1's Avatar
11 Second Club
iTrader: (20)
 
Joined: Oct 2006
Posts: 3,131
Likes: 0
From: Virginia
Default

Nor would a bad cat
WTF are you serious???

to the op yes a bad "clogged"cat will cause your car to run bad....usually a notice in power is common.....ive seen the insides of the factory cats comeapart and cause cars to barely run....

if the code said the cat was bad its normaly bad....but the rear o2s will not affect performance in any way.....
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

7 Most Reliable High-Performance Engines GM Has Ever Built

 Verdad Gallardo
story-1

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

 Verdad Gallardo
story-2

6 Common C5 Corvette Failures and What's Involved In Repairing Them

 Pouria Savadkouei
story-3

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

 Verdad Gallardo
story-4

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-5

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-6

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
story-7

Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

 Verdad Gallardo
story-8

Awesome K5 Blazer Restomod Comes With C7 Corvette Power

 Verdad Gallardo
story-9

10 Camaros You Should Never Buy

 
Old Jul 9, 2007 | 11:23 PM
  #9  
mglooper's Avatar
On The Tree
iTrader: (5)
 
Joined: Jun 2007
Posts: 153
Likes: 0
From: midland texas
Default

I had something pretty similar to this when i ran Walmart gas....I just put some injector cleaner in though and it ran pretty well. After that i got the better gas and it has been fine ever sense
Reply
Old Jul 9, 2007 | 11:39 PM
  #10  
tylerdj's Avatar
TECH Fanatic
iTrader: (31)
 
Joined: Sep 2004
Posts: 1,912
Likes: 0
From: Amarillo, TX
Default

Originally Posted by 68chevypu
really? its that high now. damn last I heard it was like 8/80 but thats cool
Yea...I think it was around December that they sent out letters to everyone stating that they were extending the warranty to 10/120.
Reply
Old Jul 10, 2007 | 02:07 PM
  #11  
68chevypu's Avatar
Launching!
iTrader: (18)
 
Joined: Aug 2005
Posts: 203
Likes: 0
From: Stockton CA
Default

Originally Posted by 5_02ls1
WTF are you serious???

to the op yes a bad "clogged"cat will cause your car to run bad....usually a notice in power is common.....ive seen the insides of the factory cats comeapart and cause cars to barely run....

if the code said the cat was bad its normaly bad....but the rear o2s will not affect performance in any way.....

wow sorry. My mistake. Never had to deal with them before.
Reply
Old Jul 10, 2007 | 04:49 PM
  #12  
px33transam's Avatar
Thread Starter
Staging Lane
 
Joined: Jan 2006
Posts: 73
Likes: 1
From: Rices Landing PA
Default

I called the dealer today and they said they needed my VIN # and they could tell me wheather I was under warranty or not. I only have 60k miles on the car and its a 2000 so it should be covered. My car seems ok now but I cleared the codes and they came back and the car sometimes feels like it falls on its face a little during slow acceleration but put her to the floor and she runs great.
Reply
Old Jul 10, 2007 | 05:37 PM
  #13  
2001NBMZ28's Avatar
TECH Senior Member
 
Joined: Dec 2001
Posts: 5,399
Likes: 3
From: Jacksonville, FL
Default

Are you throwing P0420 and/or P0430? I'd leave them stored. If something else might not be the cat(s), and the dealer will charge their diagnostic fee - and for any repairs.
Reply
Old Jul 10, 2007 | 07:32 PM
  #14  
px33transam's Avatar
Thread Starter
Staging Lane
 
Joined: Jan 2006
Posts: 73
Likes: 1
From: Rices Landing PA
Default

I just deleted them thinking the whole fuel injector/octane boost thing is why it threw the codes but they came on again so maybe there is a problem or I messed something up. As far as the #'s on the codes the guy at advance auto didnt let me see the machine he just said passenger cat and both rear O2 sensors were bad. I will find out tommorrow when I call them with my Vin and then they scan it at the dealer. You think I should put her back to stock before I take it to the dealer or does the hypertech not void any warranties?
Reply
Old Jul 11, 2007 | 12:38 PM
  #15  
2001NBMZ28's Avatar
TECH Senior Member
 
Joined: Dec 2001
Posts: 5,399
Likes: 3
From: Jacksonville, FL
Default

I'd return it to stock tune before seeing a dealer - believe hypertech manual recommends it in their instruction booket too.
Reply
Old Jul 11, 2007 | 04:12 PM
  #16  
px33transam's Avatar
Thread Starter
Staging Lane
 
Joined: Jan 2006
Posts: 73
Likes: 1
From: Rices Landing PA
Default

Putting the car back to stock and I have an appointment next Friday to get new cat installed. My dealer said the warranty is for 80k miles or 8 years but that doesnt matter I'm still covered.COOL!!!!!
Reply
Old Jul 11, 2007 | 04:46 PM
  #17  
2001NBMZ28's Avatar
TECH Senior Member
 
Joined: Dec 2001
Posts: 5,399
Likes: 3
From: Jacksonville, FL
Default

Dealer obviously didn't get the memo. LOL
Reply




All times are GMT -5. The time now is 12:51 PM.

story-0
7 Most Reliable High-Performance Engines GM Has Ever Built

Slideshow:These GM engines didn't just make huge power, they survived abuse, boost, track days, and six-digit mileage with a reputation for refusing to quit.

By Verdad Gallardo | 2026-05-21 16:45:27


VIEW MORE
story-1
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-2
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-3
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-4
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-5
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-6
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-7
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE
story-8
Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Slideshow: A heavily reworked 1972 K5 Blazer swaps its off-road roots for a low-slung street-focused build with modern V8 power.

By Verdad Gallardo | 2026-03-09 18:08:45


VIEW MORE
story-9
10 Camaros You Should Never Buy

Slideshow: There are thousands of used Camaros on the market but we think you should avoid these 10

By | 2026-02-17 17:09:30


VIEW MORE