horrible gas miliege!!!! 70 miles on 1 tank!!!!!

[JoEgsX90]

Ok guys can look at my mods in my pro, 6-bolt block bored .20 over and a 2g head 5 angle valve job ect... i have 190 rewired fuel pump with STOCK injectors running only about 13 PSI. I believe my front o2 is bad witch im about to replace shortly but could that cause such a horrible gas milege problem? Also i should add all my emitions line have been taking out , and i believe egr has a block off plate. Any ideas here/??

 

[Boost92awd]

Bad Plugs, wires, o2 sensor, air filter,PCV valve,wrong tire pressure can all cause bad MPG.

 

[talonDSMerr]

A bad o2 sensor will destroy your gas mileage. Do you have a way to log it? Replace it asap, then see if mileage increases.

 

[zhjiln]

there are lots of factors ...but the one that steals the most MPG is a faulty front O2 sensor.....

 

[Dsmj89]

Most likely your front o2 sensor is bad.

 

[kenamond]

Could also be a bad boost leak. If the O2 sensor is good, do a boost leak test. Heck, if the O2 sensor is bad, do a boost leak test anyway.

 

[92_talon_awd]

^^I think he meant to say if the front O2 sensor is bad, do a boost leak test anyways .

 

[j-jamrod]

hole in the gas tank.... or some bosy is stealling your gas at night...

 

[spyderturbo007]

Any CEL's?

 

[solidviper89]

Could be your 02 sensor or a gas leak somewhere in the fuel system.

 

[Ahsieh2]

some bosy is stealling your gas at night...

I would have to say this is a cause of poor gas mileage I have not thought of.

 

[JoEgsX90]

haha, yea well first thing i did was cheak underneath the car to see if i had hole!!! I knew my gas mileage was going to be bad withough emition and ect.... but dam!!! yea i think my o2 sensor is bad, im using a palm logger on palm and stein and its reading 0.01 to about 0.05 something like that. ??? what do you guys think?

 

[JoEgsX90]

Yea i have couple cells actally im throwing a egr valve code because i have it blocked off. Im throwing a REAR o2 sensor code, because i took it off to put my Wideband for the meantime. Im also throwing i think it was fuel pressure sensor witch i have disconect also so its throwing that code.

 

[spydermanX98X]

I dont know how you guys suggest testing for a gas leak, gas evoporates very quickly so its unlikely he'd ever see the leak, how would you go about testing for that.

 

[kenamond]

If your O2v is reading that low, I'd say it's shot. It should read around 0.5v during idle. Try oxygencensors.com. Prices are pretty good.

 

[spyderturbo007]

Mack has a spelling error in his link.

It's www.oxygensensors.com

 

[kenamond]

Mack has a spelling error in his link.

It's www.oxygensensors.com

Oxygen censorship!!! Is that a synonym for suffocation?

 

[spyderturbo007]

I was thinking the same thing. I just figured it was politically incorrect to talk about oxygen sensors these days.

 

[nitrous16v]

our 98 gst had a ck eng light every couple days and it was code 0170 i think, it was a lazy front 02 sensor.It ran great but milage stank,so i ordered the denso from www.oxygensensors.com (it was like 54 buck shipped!) and the light went away and mileage has increased. not dramaticlly but better considering the mods done im not sure what kind of mileage we should get with it. stock but factory new bottom end,stock head,ported exh manifold,fp T28 turbo w 17lb actuator,ported 02 sensor housing,3" thermal from turbo back,k&n fipk,16-17lbs of boost,dave brode upper ic pipe with 1st gen bov,intake tube return restrictor removed, new fuel pressure reg,still have to install 04 evo fuel pump and rewire kit from Forced Performance Turbochargers and i put a clutchnet yellow pp and their carbon pad disc in with a fidanza alum flywheel.

 

[JoEgsX90]

thanks guys. Im going to put in ther o2 sensor hopefully somtimes this week hopefully see some difference