probably a dumb question.
Thread Starter
On The Tree
Joined: Dec 2008
Posts: 132
Likes: 0
From: Youngstown, Ohio
probably a dumb question. working on putting long tube headers on at school and with the ory i have no cats so no after cat 02s.... my instructor said that the 02s control the fuel or somethiung and without the rear 02s i'm not going to get the hp gains i'm hoping for. what do you guys think? i figure you have personal expierence with these cars. where as he does not. sorry for the noob question.
thanks,
-Brett
thanks,
-Brett
the lack of O2 sensors will affect the performance. you need to do one of 2 things. you can either weld on some bungs to match the ones on your old manifolds or you can hook up an O2 simulator
Teching In
Joined: Oct 2008
Posts: 45
Likes: 0
From: Clovis, NM
The O2's before the cat control everything you are worried about. The O2 after the cat is only is there to monitor air coming out of it to ensure the cat is doing it's job. Basically it will only set a SES light to let you know that the cat is bad. It will affect performance in no way.
Teching In
Joined: May 2007
Posts: 5
Likes: 0
From: Charlotte, NC
I think what he is saying is that his current setup (w/ manifolds I assume) does NOT have the after cat O2 sensors... If that is the case, then there is no need to put any "after cat O2s" w/ your new setup either.
yea the o2's upstream ( the ones in the actual exhaust manifold) are the only ones you need.
the ones downstream ( behind the cat) do nothing, and only throw a code for ems. purposes.
dont wry bout it
the ones downstream ( behind the cat) do nothing, and only throw a code for ems. purposes.
dont wry bout it
Trending Topics
If your car is a 96-7 and it HAD after cat O2s they have no impact on performance as, just a couple of the guys who replied before me said. I would recommend a tune over sims because you can get performance from a tune and sims is $100 just to shut off a CEL, wouldn't it make more sense to spend a little more and gain performance.
You can NOT use O2 sims BEFORE the cats.
I don't know what hitmanws6 was talking about, then again neither does he.
Put sims up by the manifold and best case scenario is a code that will hurt performance, worst case is improper fueling which can most definetely do harm.
You can NOT use O2 sims BEFORE the cats.
I don't know what hitmanws6 was talking about, then again neither does he.
Put sims up by the manifold and best case scenario is a code that will hurt performance, worst case is improper fueling which can most definetely do harm.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
Launching!
Joined: May 2007
Posts: 216
Likes: 0
From: knoxville tn
does anyone here tune without the o2's. i was thinking about it because my engine has slightly higher compression and im running nitrous and would like to run race fuel when i spray. but the race fuel kills o2's right? so what do people do in that case.
High compression and nitrous?
How high are we talking? What else do you have done to need race fuel?Lots more info needed.
Launching!
Joined: May 2007
Posts: 216
Likes: 0
From: knoxville tn
i dont know the exact compresion but it does have flat top pistons and the heads have been milled. im guessing at least 11:1. its a 94 lt1. 306 cam. i have a 150 shot on it now and it spark knocked bad. so i put a 685 box on it with 8 deg pulled out when the nitrous is on. i would think if i had some race fuel it would help with that. or just turn down my timing but that kills power.
