exhuast headers??

[lbguy53]

would exhuast headers mess up my gas mileage?? if not do i have to install a intake for the headers?? or can i just stick with my regular air filter?

[JBIZZ]

It all depends how you drive, probably unnoticeable. You don't have to to have an intake, but in conjunction with the header you'll get better performance gains. Same with axle-back muffler. If you are specifically looking for better MPG I would recommend the NST lightweight pulley kit.

[Tamago]

if you want better mileage, drive slower. modifications rarely help

[AlexNet0]

and BTW its "header" not "headers", we dont have a V pattern engine.

[Yaris Hilton]

I don't think either headers, a cat-back exhaust, or an intake manifold swap will much affect your mileage IF everything else stays the same. But it won't. Put performance mods on, and you're going to drive in a "sporty" way that will suck the gas down faster. And if you're not going to do that, you have nothing to gain from any performance mods, anyway. (I think you have mighty little to gain from them in any case.)

[Tamago]

and without a re-tune of the ECU, all of that "better breathing" is going to waste.

[jmagdiel]

Once upon a time were all the exhaust manifolds were made of cast iron, with short runners and mismatched ports and the first step for better performance and miliage were the headers. Then you have to enrichen the mixture because of the increased excavenging lean the mixture too much.

Now nearly all new cars came from the factory with tubular exhausts, but still too short for some real advantage, as they are a compromise for cheaper manufacturing.

So far the only header for the Yaris that will bring some advantage is the TRD one, but this one is really expensive.