98 z28 w/ new headers, lost hp
Thread Starter
Staging Lane
Joined: May 2004
Posts: 78
Likes: 0
98 z28 w/ new headers, lost hp the benchmark:
ls1 98 a4 3.42, hypertech tuning (not fuel curve, but rev limit, shift firmness)
some lt headers(pacesetter), lid, freemods, cutout...
lt1...a4 2.73...cutout...k and n intake
3 races, tied all three times, no pull what so ever
before headers the ls1 raped the lt1
now wiht headers getting 8 codes:
low voltage, too lean , misfire cyl 5
so my questions:
1. what does a lt1 with cut out and intake dyno?
2. why the misfire, whould the lean codes create it?
3. what would solves the problem?
4. what should the ls1 be putting down if it works properrly
with a tune???
the answers i came up with
1. 260-280
2.the shitty extensions on the 02 sensors
3. some ngk 55s and new 02 sensors or real extenders and use the o2s from the back
4. 320/ 330
my friend is not very happy after all his money spent on the headers
ls1 98 a4 3.42, hypertech tuning (not fuel curve, but rev limit, shift firmness)
some lt headers(pacesetter), lid, freemods, cutout...
lt1...a4 2.73...cutout...k and n intake
3 races, tied all three times, no pull what so ever
before headers the ls1 raped the lt1
now wiht headers getting 8 codes:
low voltage, too lean , misfire cyl 5
so my questions:
1. what does a lt1 with cut out and intake dyno?
2. why the misfire, whould the lean codes create it?
3. what would solves the problem?
4. what should the ls1 be putting down if it works properrly
with a tune???
the answers i came up with
1. 260-280
2.the shitty extensions on the 02 sensors
3. some ngk 55s and new 02 sensors or real extenders and use the o2s from the back
4. 320/ 330
my friend is not very happy after all his money spent on the headers
Last edited by deetsnai; Dec 13, 2004 at 04:29 AM.
I had similar problems after my header install. Car felt very sluggish to. I was throwing codes for o2 sensors and missfiring. I ended up buying some new corvette o2 sensors cause the wires are a lot longer and solved everything. My old O2's had about 85K on them and it was nice to get rid of the stupid o2 extensions.
A lot of LS1's require tuning after a header install. His A/F ratio is probably way off. The items mentioned already will probably help the condition, but a custom tune may be required.
Teching In
Joined: Nov 2004
Posts: 41
Likes: 0
alright, i have joined the crowd. i just installed QTP's headers, ORY, and 02 extensions. my car backfires and sputters down low, then feels a little sluggish in the upper rpm.
so, whats up?? tune?? my extensions looked good, i ran them to the front 02s, but someone said something about running them to the rears?? also, did you just leave the unused plugs open under the car.
ideas and help.... plz.
so, whats up?? tune?? my extensions looked good, i ran them to the front 02s, but someone said something about running them to the rears?? also, did you just leave the unused plugs open under the car.
ideas and help.... plz.
when you change something that drastic you have to tune the car if you are lookin for it to run good. you cant expect to open up the exhaust that much and have the car automaticly feel faster. some cars can do that some cant. i have pacesetters on mine and my friend has them on his SS. its not the headers. the o2 sensors could be bad and the extentions arent crappy at all as you did it right. chances are something wasnt installed right if the tune is ok. check for cut wires. is everything pluged up? maybe one of the wires got burnt on the header. there are way too many variables here. what are all the codes word for word?
I *think* I'm experiencing a somewhat similar condition down low lately.. I had my Kooks LTs with Catted Y installed last week or so, and the car feels a bit sluggish below 2k rpms... kinda like a *loose* feeling... past 2k rpms, it screams!
I too have a 98 TA with about 100,400 miles on it now... but no codes!..
I wonder if I need a tune, new O2 sensors or both!!
How much do O2 sensors cost ? anyone have a part # ?
Thanks!!
I too have a 98 TA with about 100,400 miles on it now... but no codes!..
I wonder if I need a tune, new O2 sensors or both!!
How much do O2 sensors cost ? anyone have a part # ?
Thanks!!
Trending Topics
Teching In
Joined: Nov 2004
Posts: 41
Likes: 0
Originally Posted by BlownGTX
I *think* I'm experiencing a somewhat similar condition down low lately.. I had my Kooks LTs with Catted Y installed last week or so, and the car feels a bit sluggish below 2k rpms... kinda like a *loose* feeling... past 2k rpms, it screams!
I too have a 98 TA with about 100,400 miles on it now... but no codes!..
I wonder if I need a tune, new O2 sensors or both!!
How much do O2 sensors cost ? anyone have a part # ?
Thanks!!
I too have a 98 TA with about 100,400 miles on it now... but no codes!..
I wonder if I need a tune, new O2 sensors or both!!
How much do O2 sensors cost ? anyone have a part # ?
Thanks!!
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
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 thanks.. I got the part numbers:
GM Parts direct has'em for $61 and change each.. GM List is $123 each
LEFT O2 --> 25312197
RIGHT O2 --> 25312196
Front and Back are same.
So, I'd need 4 sensors ?
GM Parts direct has'em for $61 and change each.. GM List is $123 each
LEFT O2 --> 25312197
RIGHT O2 --> 25312196
Front and Back are same.
So, I'd need 4 sensors ?
Originally Posted by WS6FirebirdTA00
its not the headers. the o2 sensors could be bad and the extentions arent crappy at all as you did it right. chances are something wasnt installed right if the tune is ok. check for cut wires. is everything pluged up? maybe one of the wires got burnt on the header. there are way too many variables here.
A tune is the 'ideal' after a header install but not totally necessary in most cases I think.
just get the front the rears are for emissions testing, making sure the cats work so dont worry about those. get them from gmpartsdirect the ones from the parts store tend to fail easier. the sluggish feeling that low is normal becuase of tuning and you do loose some low end torque and power after headers sometimes, i think
If you get new O2 sensors I would recommend getting the rear one from an LS1 corvette they have the same plugs and the wires are a lot longer. They are only like $5 more a piece then you can get rid of the extensions and dont have to worry about them causing any problems.
Can the rear O2 sensors for the F-bodies be used as fronts and are they long enough to be used as front O2s on long tubes (like QTPs, Kooks, Jet Hots etc that have the bungs on the 'inside' (facing the trans as opposed to the doors)) when deleting the rears?
Teching In
Joined: Nov 2004
Posts: 41
Likes: 0
Originally Posted by BlownGTX
LEFT O2 --> 25312197
RIGHT O2 --> 25312196
RIGHT O2 --> 25312196
i got mine at autozone, i couldn't get the old ones out and i want to get the job finished.
On The Tree
Joined: May 2004
Posts: 105
Likes: 0
From: Ontario, California
ok i just installed the vette O2 sensors, it is still sluggish and a little wierd jerky feel to it. but it did smoothen it up a bit. do u reccomeend taking off hypertech completely? i just have the top speed, shift firmness, tire height, and thermo. would this be the problem? or do you think there is sumtin else wrong? could be spark plugs? im going to get my car scanned tomorrow and ill update whats goin on.
Thread Starter
Staging Lane
Joined: May 2004
Posts: 78
Likes: 0
Originally Posted by emanneercstahp
ok i just installed the vette O2 sensors, it is still sluggish and a little wierd jerky feel to it. but it did smoothen it up a bit. do u reccomeend taking off hypertech completely? i just have the top speed, shift firmness, tire height, and thermo. would this be the problem? or do you think there is sumtin else wrong? could be spark plugs? im going to get my car scanned tomorrow and ill update whats goin on.
There is no reason your car, or anyones car would run worse with LT headers installed. The headers arn't the problem. Something either got broken, burnt, or cut. Also... I've heard of people using the wrong bolts to bolt the headers up and cracking their heads or stripping the header bolts out. I'm sure it's a simple wiring problem that you can easily take care of and once you get it fixed you'll be supprised how much LTs wake up the LS1.