I have an exhaust leak on the Manifold/Header


If I put an aftermarket Header on, do I need a Tune or will it
bolt right on, no tune needed - Will it code?


Also curious if I do a High Flow Cat and Muffler at the same time
will I need a Tune?

Will it code the 02 sensors


Tks
Will

 

You don't need a tune for anything. What year is your jeep

 

I thought these were sd motors?

changing anything regarding intake or exhaust will alter the afr. I'd think ESP something like a manifold to header swap. I know it leaned my ls1 car WAY out doing such. and that was with a maf...

sd motors are like carbs in a big way. I'm pretty sure the o2s can only change fueling like +\- 3% or whatever.

 

1999 4.0


Will

 

That why I asked - I do LSx parts for a living and know they need a
tune after headers...

Will

 

then you already know the answer. these are sd motors. best you could do is verify with a wideband. are you a vendor on tech? I don't do lsex parts for a living but I've owned multiple lsx powered cars and dealt with them about 10 years now. love em.

looking into swapping my jeep. I just sold my 99 ws6 2 weeks ago.

 

Corvette Forum...


I can do a Corvette half asleep, but I don't know squat about these Jeep straight 6's

Will

 

You'll need a cat with an o2 bung on it

 

Pipe has a 02 before and after the cat, in the exhaust pipe already...


Will

 

Just put it on.................

 

Oh some have it on the cat

 

Yeah... Just bolt it on up...

 

You only need to tune the 4.0 if you do a stroker or super/turbocharge it... Intakes and exhausts are called "bolt on" for a reason

 

they are called "bolt ons" because they literally bolt on. not because of how they affect the engine. I'd like to see someone verify with a wideband what actually happens when doing mods like this, just to see. as stated earlier, putting bolt ons on my ls1 car took it from a solid 12.8 afr @ wot to 14.7 at only 2800 rpm. bolt ons or not that is not safe or right. the lean condition also caused 8* spark knock. also all below 3k rpm.

 

Our injectors have alot of headroom for added air.

As stated by Salad, the only time you need to increase injector size is when using forced induction or stroking it to 4.6 + liters.