[conceyted]

wtf! ok past 3 tanks of gas have been used in 6 days and i have done very little driving... the trip says im getting 8 or under miles per gallon.... what could be wrong!!??! im getting no cel....

 

[tstalontsi]

I had a similar, but not near as bad problem (like 15 highway mpg) and it turned that my fuel line was leaking where it is connected to the fuel rail. You may want to check that out.
Trent

 

[conceyted]

wheres that at? and will it show signs of leaks in the ground perhaps? there are no visable leaks

 

[conceyted]

help?!?! please?

 

[dsmfan95]

If all else fails, take it to a mechanic.

 

[migamb]

It could also be a bad O2 sensor. Find someone who has a logger if you don't and if you can't take it to the dealer. I have never heard of 8 MPG:dunno:

 

[conceyted]

help! please!

 

[tstalontsi]

no, there are not visible signs on the ground, but the engine bay would smell of gas......find the fuel filter and follow it to the fuel rail and injectors, while the car is running see if you can see any drippage. This is how I figured out what was wrong. A bad O2 sensor would also make sense (but I'm not sure about 8mpg). Hope this helps
Trent

 

[billdo_83]

You didn't do the chevy 350 swap did you?
j/k

If you cant find any gas leaks anywhere is the car running REALLY rich?
Like alot of black smoke when you get on the gas?

 

[AluH20]

I agree w/ migamb. That's the first thing I would replace.

http://www.machv.com/oxygensensor.html

 

[imoore]

I have the same problem actually. I don't know the actual number I'm getting but it's somewhere under 15 mpg, closer to 10 mpg I would guess and I have a NEW O2 sensor with less than 10k on it. I just attribute it to my 14b and a lead foot.

 

[migamb]

I think we all have lead feet. This car no matter the turbo should be getting around 20 MPG unless something is wrong obviously.

 

[imoore]

Do you know what your highway milage is? Mine is about 30 or so mpg, so that's how I know it's my lead foot.

 

[conceyted]

well i keep getting a check engine light now..... no signs whatsoever of drippage etc... what could it be?!?!

 

[imoore]

well i keep getting a check engine light now..... no signs whatsoever of drippage etc... what could it be?!?!

First thing to do is pull the code. Either find someone with a logger or do the 2G trick, which I can't remember. I believe it's somewhere in the "1000 already asked questions." Something like turn the key on and off 5 times...

Then go here:
http://membersites.namezero.com/jogauthi.nmu.edu/gi/obdiidtcu.htm
or
http://membersites.namezero.com/jogauthi.nmu.edu/gi/obdiidtcs.htm

And look-up the code.

 

[conceyted]

well the mechanic told me since i have no cat... that i have no back pressure so my o2 sensor is not reading anythign qand its just throwing all the fuel into the air fuel mixture.... so he suggests a 3 inch cat... i told him thats bullshit becasue i know a few eclipses and other cars with no cats that get perfectly fine gas milage... my o2 sensor is bad IMO what do you all think?

 

[imoore]

well the mechanic told me since i have no cat... that i have no back pressure so my o2 sensor is not reading anythign qand its just throwing all the fuel into the air fuel mixture.... so he suggests a 3 inch cat... i told him thats bullshit becasue i know a few eclipses and other cars with no cats that get perfectly fine gas milage... my o2 sensor is bad IMO what do you all think?

That's a load of bullshit, I have no cat and I'm fine on the highway, just not when I get on it

It can never hurt to put in a new O2 sensor, so you can give that a shot.

 

[AluH20]

I'm not sure about what's available for the 1995+ years. Try two... no... three things:

1. Look for an O2 Sim (when I was into modding my Camaro... the 1996 year models had an O2 sensor behind their catalytic converters and when they upgraded their exhausts they'd buy an O2 sim to give a fake signal).*

*But I am not sure about that part for a DSM.

2. Just replace the O2 sensor.

3. Check your fuel rail. It's a metal bar behind your engine's valve cover (the DOHC piece) and in front of your intake manifold (where your upper intercooler pipe goes into).

 

[conceyted]

already checked those... if the problem persists after these 02 sensors whats this thing about a fake signal for 02 sensor?

 

[imoore]

already checked those... if the problem persists after these 02 sensors whats this thing about a fake signal for 02 sensor?

What the rear O2 (post-cat) sensor checks for is simply a different signal than the pre-cat one, I just wrapped mine in tin foil and duct tape and wedged it above a heat shield, does the same thing as a fake signal.