Crappy mpg - 01 civic?

[LTDirty]

A long time ago I had a completely stock 2001 civic ex 5 speed over 200k miles on it. It was amazing on gas. I could easily get over 500 miles per tank.

I just recently bought another 01 civic ex, however it is not stock. Here is the specs:
203k on the body and around 90k on the replaced stock motor. Same D17 y8 i believe.
5 speed.
light weight pulley
Exedy stage 1 clutch
short shifter
tein coilovers
No name Full exhaust(headers back)
04 bumper and tailights.
Fresh full synthetic oil.

I can get maybe 400 miles all highway. No engine light. Just an abs light and a srs light for the rear seatbelt buckle which i plan on taking to the dealer soon. Any ideas?

 

[R3dline]

exhaust will hurt mpg on 4 bangers cause they need backpressure, could be using cheap gas, could need the injectors cleaned, could be a tone of things, id start with a simple tune up, change the plugs, wires, oil change, clean the injectors, etc. see if that helps...

 

[LTDirty]

exhaust will hurt mpg on 4 bangers cause they need backpressure, could be using cheap gas, could need the injectors cleaned, could be a tone of things, id start with a simple tune up, change the plugs, wires, oil change, clean the injectors, etc. see if that helps...

I'd rather have a stock exhaust anyways haha. Ill do a tune up and find a stock exhaust!
Oh and it also has a really nice Cold Air Intake.

 

[lowlife9]

put a stock airbox back on it.also if the motor was replaced they mite swapped oxygen sensor for aftermarket or high mileage ones dirty oxygen sensors will give you bad mpg.

 

[lethal6]

My d-series got worse gas mileage when I put the cold air intake on it. Not all that much, but it was around 5 mpg which can add up a lot.

 

[LTDirty]

My d-series got worse gas mileage when I put the cold air intake on it. Not all that much, but it was around 5 mpg which can add up a lot.

Really? Ill have to get a stock intake and test this out! Thanks for replying!

 

[emerican]

before i replaced the intake if you like it i would try the oil change, full tune up, change all the filters, clean the injectors and fuel system

 

[LTDirty]

before i replaced the intake if you like it i would try the oil change, full tune up, change all the filters, clean the injectors and fuel system

Thats exactly what I was going to do! But my engine is f**ked so I have to buy a new one haha.

 

[hondavtec01]

I have a stock intake for a 2001 Civic EX that I will sell for $25.00 plus shipping if your interested.It came off my 2001 when it only had 15,000 miles on it so it is like new. email me at crussell22@yahoo.com if interested.Thanks

 

[HeX]

In addition to everyone else's accurate comments, skim through the "Better MPG" link on my signature. So what miles per gallon and/or tankful are you getting?

 

[lowlife9]

looking at your list for number #2 i was under the impression that hot air gives you better mpg and cold air gives you worse ???

 

[deininger21]

i have a 2001 honda civic ex and i used SeaFoam and it increased my mpg and also clean up my engine but it only last a couple months. it also helps burn away bad emissions.