Real shitty gas milage - something wrong!?

[John Hartman]

I believe you will still be finding something wrong.  Possibly the coolant temp sensor or something big.  Even a bad O2 sensor normally won't cause this horrid of mileage.

[Brett Haviland]

yeah and wioth obd2 you would have a code more then likely if a bad o2 sensor was the problem.

[John Hartman]

especially on a 2g.

[Sy Haw Wong]

UPDATE:

So I this is the second fill up since fixing my car, and officially I ran 229miles and filled up 13gallons (49.4L).  So now I am getting about 17.6mpg mixed city/highway.  Which is an improvement I guess.

Obviously the 21mpg factory rating is a little BS, but I will take 17.6 over 11.

[Brett Haviland]

should get better then that still i would say...

but a lot of it depends on how your driving the car.... and in city traffic kills mileage.

[John Hartman]

as does cold weather.  The EPA ratings are taken on a closed circuit course designed to mimic a normal commute, but it does not.  So if you can get the EPA rating you either are trying really hard or your normal driving commute is super easy on fuel.

I believe your car is still falling a bit short tho, as my Mazdapseed that weights over 3700lbs with me in it gets noticably better mileage than that and has a bigger engine.

[Remi Raymond]

It also has decades more modern development than the 4g63, not to mention direct injection, you cheater

[Sy Haw Wong]

It also has decades more modern development than the 4g63, not to mention direct injection, you cheater

Touche ~ 

Plus my car is 13 years old.  I don't expect it to be comparable to modern cars.

I have been running accessories and the cold probably has a lot to do with mileage factors.  Not to mention VanCity traffic is pretty...horrendous. 

[Brett Haviland]

and its fwd too!  theres a lot less driveline drag on your car compared to a awd one.

[Kristopher]

UPDATE:

So I this is the second fill up since fixing my car, and officially I ran 229miles and filled up 13gallons (49.4L).  So now I am getting about 17.6mpg mixed city/highway.  Which is an improvement I guess.

Obviously the 21mpg factory rating is a little BS, but I will take 17.6 over 11.

The way I figure it is you should be realistically achieving 19 mpg US City when adjusted for the new testing procedures.
Your 17.6 mpg imperial translates to nearly 15 mpg US, hence you're 7.5 mpg short (and consequently 4.85 l/100km less).

How did the plugs look? As has been suggested, might have a leaky injector.

http://www.fueleconomy.gov/feg/findacar.htm
http://www.tdiclub.com/misc/conversions.html

[daniel sanat]

this got me looking at the gauge more often , and actually i noticed that i went through the lower quarter tank in just 40km . normal ?

[John Hartman]

the bottom "half" of the tank is tiny.

[daniel Dee]

Eprom chip with an extra lean cruise..
I believe that John has some experience with this.

How about Cyclone Dual Runner Intake manifold (factory).
There has to be some mileage gains there.
Probably won't fit on 2g.
MSD style ignition...

Anybody believes in the tornado intake???

[Brett Haviland]

Anybody believes in the tornado intake???

lol, u made my day.

[John Hartman]

maybe some non engine related items too.

Low tire pressures?

siezed/partially siezed caliper?

bad wheel alignment?

dragging ebrake?