Protege5 header
 

Does a header improve fuel economy at all or is it strictly for performance??

it can. There are a few ways it could improve fuel economy and a big one that it would hurt.

1. It helps by reducing the weight of the exhaust maniolfd and pre-cat. Almost a 10lb savings if not more. Less weight = better milage

2. IT helps in that it makes your engine more efficient. More efficient = better milage

3. It hurts in that with the increase in power most people tend to use more of the gas pedal.... more gas pedal = worse mileage

4. Without the proper MIL eliminator you will throw a CEL and cause the car to run richer. Running Richer = worse mileage.

That about covers it.

You can get a MIL CEL eliminator or a spark plug nonfouler to fis the CEL.



The header may have made me mash the gas more often but I am an agressive driver anyways. I mash the pedal on anything I can.

It is a very simple install. Be sure to get a new donut gasket.

It's a CEL from the 2nd oxygen sensor.. I ran for about a year with the 2nd sensor unplugged and routinely got 36mpg highway, not running noticeably richer (didn't have a wideband at the time)

Even if the header increases gas mileage (I'm sure it does, I got super gas mileage when my car was all NA modded), don't let that be one of your top reasons for getting one, because think of how many miles you'd have to drive for the cost to balance out.

It's like the Civic hybrid.. at least the 2004ish generation ones (7th gen civic), you'd have to drive 180,000 miles for the gas savings to equal the extra cost of buying a hybrid. -- that's making the assumption that the maintenance costs will be just as low for a hybrid (they aren't), that the batteries would hold the same charge year after year after year (they don't at all), among others.

Perhaps the CEL from a bad reading affects the car differently than the CEL from having no 2nd sensor at all? If so, get the ractive header and just don't have the 2nd sensor plugged in until you get a catted midpipe with an extra bung to install it in (post cat).