I have a 94 Honda civic..I'm only getting 150 miles to a a tank on a 12 gallon tank..not sure what the problem is...I have replaced the air filter, fuel filter, spark plugs and wires..not sure what else to look at

 

Are there any modifications to the car? What kind of driving are you doing? Is it MT, or AT?

 

It's a manual and only mod is a intake system

 

I do normal driving I don't beat on it or race or nothing

 

O2 sensor may be bad.

 

Throwing money at parts isn't the best approach. All of those parts minus the fuel filter could've been inspected first to determine their condition.

A failing 02 sensor will definitely cause bad fuel economy but I'd expect you'd see a CEL first; but that's not always the case. When was the last time the thermostat was changed?

 

The thermostat was also replaced...I have no cel lights on

 

Thermostat has nothing to do with fuel economy

 

check the o2 sensor