Okay well i have a 97 civic coupe and it has a vtec b18 dohc not really sure what kind of b18 it is though but my mpg seems to be pretty terrible cause i can only drive the car 175 miles until it runs out of gas and that with a full tank. What's wrong here?

 

Learn how to drive?

Seriously though, we need A LOT more detail to actually help you. Things like what is done to everything, what ECU, what type of driving you do, and so on... Since you have a heavily modified engine, lower gas mileage is expected.

 

My bad I'm new to this forum thing so just bare with me for a sec. All i know about my car is that the ecu probably still stock cause the guy i previously bought it from didn't really put much thought into the engine swap ill try and find out more info motion on that subject and really check out the ecu but as far as drive my car its a mix of highway and city but mostly just short trips to near by places.

 

Last tune up?
Check engine light on?
Check ignition and cam timing?