Okay, so a while ago, I decided to install a ricer light display (aka narrow-band air/fuel ratio guage)... ever since it's been installed, it's been reading completely lean (If I stand on the throttle, it'll go up to a little leaner than ideal).Please don'tsuggest thatI installed it wrong.. I checked and re-checked... it's right lol... The last time I filled up my tank, my car had gone 113 miles on 8.5 gallons of gas. For those of you that don't feel like calculating that, it's 13.2941 mpg (all city driving, but still... ). I'm thinking the o2 sensor is either dirty or worn out; the only thing that is sort of throwing me off is that if the o2 sensor is bad, shouldn't it throw a CEL (which mycar isn't showing)?

Any suggestions/confirmation would be greatly appreciated.... I don't really want to spend $100 where it isn't needed. I'm really starting to get tired of Dodge Viper fuel efficiency in a Honda Civic

 

is your check engine light bulb good? make sure it illuminates with key on, if so and you're su****ious of the o2 run tests to verify proper operation, otherwise maybe your air/fuel gauge is calibrated wrong or defective.

 

I wouldnt believe what that gauge says...ever. Unless you're running a wideband, its not going to be right

However, 13mpg is not right, even in the city. Are you driving it really hard?

 

yeah dont beleive what a narrow-band syas. Unless its a wideband, its just a light show (liek you said earlier man). Unless you got the wideband, dont really trust it, i've always heard of narrow bands fluxuating alot anyway, and if you have a header/custom exhuast, your sensor is probably freaking out anyway. Dont worry about it man.