Does LT Header require a tune?
Thread Starter
Racer
Joined: Oct 2016
Posts: 437
Likes: 61
Does LT Header require a tune?
Hey guys,
i was wondering if installation of LT Header require a tune?
I'm taking about LT Headers with high flow cats.
What about CEL that might come up if using without a tune?
Thanks
i was wondering if installation of LT Header require a tune?
I'm taking about LT Headers with high flow cats.
What about CEL that might come up if using without a tune?
Thanks
SUBVETTE
Joined: Jul 2006
Posts: 3,841
Likes: 93
From: San Diego CA
The issue with header installation is moving the location of the cats which will usually cause a code to come on because they don't heat up fast enough when moved further away from the engine. That's why a tune is almost always performed to turn off the cats O2 sensors as well as to optimize the engine performance with the new higher flow exhaust.
Burning Brakes
Joined: Nov 1999
Posts: 1,221
Likes: 59
From: Abingdon VA
Would be nice to hear from the tuner guys on what they change in a tune specifically for long tube headers since the E92 and E92A has the torque models.
Typically, I would guess turning off the secondary O2 sensor CEL is a given with no cats or aftermarket cats. A MAF tweak might be needed for part throttle IF the Ltrims drift over a couple of % positive. KR MIGHT need less sensitivity due to header "noise". WOT probably does not need any more fuel due to COT and IVT enrichment. But , if you are adding headers and a tune , COT will be turned off so wot MAF will probably need a tweak. I bet somebody has put on headers, deleted all 4 cats , added a cai and left the tune pure stock somewhere and is doing ok......not correct or optimum.....but ok.
Typically, I would guess turning off the secondary O2 sensor CEL is a given with no cats or aftermarket cats. A MAF tweak might be needed for part throttle IF the Ltrims drift over a couple of % positive. KR MIGHT need less sensitivity due to header "noise". WOT probably does not need any more fuel due to COT and IVT enrichment. But , if you are adding headers and a tune , COT will be turned off so wot MAF will probably need a tweak. I bet somebody has put on headers, deleted all 4 cats , added a cai and left the tune pure stock somewhere and is doing ok......not correct or optimum.....but ok.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Race Director
Joined: Jul 2007
Posts: 10,961
Likes: 2,643
From: Texas Hill Country
Tune needed mostly for CEL issue rather than fueling.
onfire is correct that they can also create a false knock issue but care should be taken when desensitizing the knock sensors.
onfire is correct that they can also create a false knock issue but care should be taken when desensitizing the knock sensors.
Burning Brakes
Joined: Nov 1999
Posts: 1,221
Likes: 59
From: Abingdon VA
Burning Brakes
Joined: Nov 2016
Posts: 774
Likes: 91
The issue with header installation is moving the location of the cats which will usually cause a code to come on because they don't heat up fast enough when moved further away from the engine. That's why a tune is almost always performed to turn off the cats O2 sensors as well as to optimize the engine performance with the new higher flow exhaust.
Race Director
Joined: Jul 2007
Posts: 10,961
Likes: 2,643
From: Texas Hill Country
I read some where it's against the law to tune out the cats nowadays, at least on those 'canned tune' handhelds. I guess the local tuner does what he wants. but in NY if a Sheriff looks underneath and see's strait pipes it's a 2500 dollar fine. I guess 'fake' cats can be used wisely.
Burning Brakes
Joined: Nov 2016
Posts: 774
Likes: 91
Race Director
Joined: Jul 2007
Posts: 10,961
Likes: 2,643
From: Texas Hill Country
Burning Brakes
Joined: Nov 2016
Posts: 774
Likes: 91
the Dukes of Hazzard was filmed in California so I don't think you're right. the setting was in Georgia and according to this: http://www.dmv.org/ga-georgia/smog-check.php I think you might be wrong from that perspective as well.
Race Director
Joined: Jul 2007
Posts: 10,961
Likes: 2,643
From: Texas Hill Country