# Retune after header install???



## pocketmaster (Feb 26, 2010)

I'm looking to install some Kooks LT's and Im curious if I will be throwing codes after the install?? I currently have a custom HP tune w/ stock headers. 05/M6


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## aarons1k (May 23, 2008)

pocketmaster said:


> I'm looking to install some Kooks LT's and Im curious if I will be throwing codes after the install?? I currently have a custom HP tune w/ stock headers. 05/M6


Not w the headers but if you install cat-less mids then yes


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## 87GN06GTO07IRL (Aug 10, 2009)

You might get a lean code.


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## Poncho Dan (Jun 30, 2009)

It'll probably run a little off until you get it retuned. I personally wouldn't recommend not tuning any mod. Some guys think they can get away with porting the TB without tuning too, but trust me, small changes do make a difference. There's cars that hum along, and then there's cars that sing.

I'd even go so far to say you might need a little AFR adjustment after having the injectors cleaned, but I haven't done it yet so I don't know. I've seen the pulsewidths on the injectors drop by as much as 1ms after a cleaning, so it might have an effect.

I couldn't believe how many LS powerplants I saw at a local show with an exhaust competition that blew black smoke when they goosed it. Mine didn't.


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## pocketmaster (Feb 26, 2010)

Poncho Dan said:


> It'll probably run a little off until you get it retuned. I personally wouldn't recommend not tuning any mod. Some guys think they can get away with porting the TB without tuning too, but trust me, small changes do make a difference. There's cars that hum along, and then there's cars that sing.
> 
> I'd even go so far to say you might need a little AFR adjustment after having the injectors cleaned, but I haven't done it yet so I don't know. I've seen the pulsewidths on the injectors drop by as much as 1ms after a cleaning, so it might have an effect.
> 
> I couldn't believe how many LS powerplants I saw at a local show with an exhaust competition that blew black smoke when they goosed it. Mine didn't.


I noticed when I got mine dyno tuned after getting my new clutch installed it would puff white smoke mildly when he got on the throttle. With each pass he made while tuning it, it seemed to change. Im assuming it was the adjustments that were being made, but I could be wrong.


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## Poncho Dan (Jun 30, 2009)

You're almost guaranteed to never get the tune right on the first ECM flash, it usually takes 3 or 4 calibrations to get it dialed in if you know what you're doing.


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## pocketmaster (Feb 26, 2010)

Poncho Dan said:


> You're almost guaranteed to never get the tune right on the first ECM flash, it usually takes 3 or 4 calibrations to get it dialed in if you know what you're doing.


What kind of HP gain should I expect from installing the Kooks headers. Currently the only mods are K&N CAI, Custom HP Tune, X-pipe w/ muffler delete and stage 2 Monster clutch w/ lightweight fly-wheel. Other than that its pretty much stock. I dyno'd at 367 RWHP 383trq with the tune and stock headers.


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## Poncho Dan (Jun 30, 2009)

30 or so seems to be the general gain. Give or take a few ponies.


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