I have a 96 civic dx auto. I get 29 mpg mostly highway. I think my stock manifold has a crack and the cat maybe a little clogged. I ordered a header and im gonna instal wothout the cat. Yes,I know its gonna throw a code but I dont care about that. So....my question is do you think ill pick up some mpg with this header vs cracked manifold,clogged cat?

 

i would think so but im not very knowledgable lol..

 

I doubt having no cat will increase your MPG.
i say get a cat.. so you can pass inspection. because later on your gonna have to get a cat either way...
and how will you know when your CEL is trying to tell you something else? (since it will always be on...)
but idk.
thats wat i think.

 

vs. having a cracked manifold you'll pick up a little MPG, but it probably won't be noticeable. vs. having a cat there is not really a difference in MPG.

 

You may see a significant increase in mileage by replacing the cracked header, if the crack is allowing outside air to mix with the exhaust gas.

 

Running with no cat is not only illegal, but also hazardous for you and others around you. I'm no tree-hugger but that is plain stupid.

 

Thanks guys im gonna have the CATLESS header on fri for install. I cant wait to get in on. Hey stiffler....cant wait to have that CATLESS header on my car oh yeah. stickler

 

Go back to playing with domestics. I have no grief with you being a douchebag until you're close enough for me to do something about it.

And as far as the header goes - keep checking your idle. It's best to do it in an unventilated garage so you don't get inconsistent air in it. Run it for about 10 minutes and keep checking that idle.



wahmbulance

 

Actually, without the cat you'll throw a CEL code which will cause the computer to put your engine in limp mode, decreasing your overall performance and MPG. Best to put it back together right instead of spending your money on decreased performance.

 

omg, i finally see someone who isnt an internet gangster! respect..

@senicalj4579: you must think a loud car makes you fast huh? i bet you get off when people look at you drive past.. their laughing and pointing at you, their not saying cool car.. gtfo of the interwebz