13 MPG 95' TSi AWD!!!!

[Hybucci]

I am getting really bad gas mileage as you can probably. I got it out of the shop after having a boost leak fixed. Could they have not fixed it all the way? Will a bigger turbo hurt the gas mileage that much? Any help is appreciated.

 

[oldman]

Your profile says nothing about a bigger turbo, please update profile if need be.

 

[Hybucci]

Its up I think. Just click on my car and it should work.

 

[Hybucci]

What should I be getting close to with some normal driving if I was trying to get good gas mileage?

 

[The_EE]

Well, with my mods I am getting 22-25 highway.

I would say, check for boost leaks, check the plugs, check the o2 sensor.

 

[oldman]

Well, with my mods I am getting 22-25 highway.

I would say, check for boost leaks, check the plugs, check the o2 sensor.

And make sure that HKS isn't vented.

 

[TurkF26]

When was the last time the fuel filter was changed?? I know that in my car i was getting pretty crappy gas milage and just by changing the fuel filter it did help a lot. Also are you using cheap crappy 91 octane or are you using chevron, 76, etc... I also have noticed that the kind of gas you use does make a difference.

I hope that any of that helps!

 

[Hybucci]

The_EE: Yeah I have quiet a bit less done to my car than what you do and im getting like 190 miles to a tank roughly. I know that I have a boost leak right now but when I didnt thats the mileage it was getting.

1. Does anyone have a diagram of what the plugs should look like? The last set that I pulled out were destroyed.
2. What should I be looking for when I look at my O2 sensor (where is it located i.e.)

Oldman: How would I tell if its vented or not?


TurkF26: I will try a new fuel filter, any specific brands I should look for? I usually am filling up with 93 at any mobile, that wouldnt make that big of a difference would it.

Thanks for bearing with me guys as you can probably tell I am a noob when it comes to DSM's. I only have basic honda knowledge.

 

[TurkF26]

I only use OEM fuel and oil filters from Mitsubishi. If you dont know where the fuel filter is, its located on the firewall pretty much behind the battery towards the bottom.

The first o2 sensor is located on the o2 housing right off the turbo. The wire (if the stock heatshiled is on) runs across the top of the exhaust manifold heatshield and plugs into the engine harness right near the thermostat housing. I would say get an o2 sensor socket, pull the o2 sensor out and check to see if its totally burnt, black, etc... If you do decide to get a new o2 sensor, like i said before, i only use OEM mitsu parts and they run from 130-140 new from the dealer or 118.00 + shipping from extreme psi.

http://www.extremepsi.com/store/customer/product.php?productid=18922&cat=1060&page=1

here is also a link to a new OEM fuel filter

http://www.extremepsi.com/store/customer/product.php?productid=17890&cat=1068&page=1

hope this helps!

 

[andymoraitis]

As an addendum can buy Denso OEM quality O2 sensors from:

http://www.sparkplugs.com

They're OEM replacements, can handle leaded gas and only cost 60.00 including shipping. For price and quality, they're simply the best.

For fuel and oil filters I certainly recommend OEM pieces.

Enjoy,

Andy

 

[The_EE]

You would know if it is vented by checking to see if the blow off valve is connected to the intake.

Also, how do you drive? Do you drive nice and smooth like a grandma because if you bring it into boost a lot, you will get crappy mileage. When I do that I get about 15mpg but I dont do it often due to $2.50-$3 a gallon gas where I live. Plus.. I have the only silver GSX around and dont like to draw unneeded attention to myself.

dont worry about being new.. we were all new once. You will learn in time like all of us. I have only been in the game about a year and a half now.

 

[TurkF26]

good job there andy!! Do the Denso's last as long as the OEM ones?? A while back i tried a bosch from Autozone and it didnt last too long at all before getting all fouled up. So far for me, the Mitsu OEM ones last the longest for OEM replacements. I may have to try a Denso next time.

 

[siceclipse]

im gonna say boost leaks (very unlikely since he just got them fixed), o2 sensor (very common {remember there are 2 in your car}), Fuel Filter (VERY common), or like me a crack in the manifold.

to find out about the crack in the mainfold, use some seafoam in the intake and see if it smokes out the exhaust manifold.

 

[andymoraitis]

Denso is the OEM replacement. Some cars also use NGK's but Denso is the brand I pulled from mine at the time of replacement and it was original. Since it's an OEM piece, I think you'll find that it will last just as long. I bought mine to handle leaded but hardly ever run it so it should be good for quite a while.

The aftermarket pieces from AutoZone are Bosch and while those seem to be popular for a wideband, I wouldn't want one for my narrowband sensor.

Siceclipse: Nice catch. Pre-turbo exhaust leaks will kill performance and the loss of metered air before the O2 will certainly make the car feel like a dog.

 

[7"exhaust_tip]

not trying to thread jack, but, i jsut did what siceclipse said the other day and i found out that my exhaust manifold was leaking. Should i just buy another oem replacement one or what?

 

[siceclipse]

7"exhaust_tip:

Take this to the PM box
you have mail.

 

[Hybucci]

TurkF26: I will look at the o2 sensors tomorow.

The EE: It is not vented, it is connected to one of the upper intercooler pipes. I have all stock piping and it is the molded plastic pipe.

siceclipse: I know that it is I have a boost leak now and im thinking about redoing everything with all metal piping instead of shitty stock plastic and rubber stuff. I know that I dont have a exhaust manifold crack for sure.

1. What should the car be sounding like when im deep into the boost? When I first got it out of the shop it was a nice sounding whining than after about 500 miles I started to notice that it was starting to be more like air leaking out of an inflatable bed.

2. Are there any performance options that I should look at while im in the market for o2 sensors? I dont want to put stock stuff in if there is something else that I should look for.


Once again all help is appreciated.

 

[The_EE]

When you have the boost leaks fixed, did you take it to mitsu?

Its possible the mechanic failed at putting the hose and clamps on right. Basically you should have the clamp right passed the rolled edge of the hose so that it presses the hose into the edge when the clamp is put on. Some people fail to understand this and place the clamp too far up the pipe to the point that it doesnt seal.

I would really suggest another boost leak test.

 

[Hybucci]

No I didnt take it to the dealer b/c of way to much money, I took it to a trusted friend. It may have been something that I did while driving.

I will be doing another leak test soon. Is there a guide on how to do one on the forums here somewhere?

Would it be a good idea to go with a cheap ebay intercooler piping kit?

 

[siceclipse]

ebay intercoolers are AWESOME, however the piping is a craps shoot.
Sometimes it fits perfectly and for others they have to do modifications to the pipes to get them to fit right.

 

[Hybucci]

Any suggestion on where to go for a prebent set of pipes?

 

[Hybucci]

http://cgi.ebay.com/ebaymotors/OBX-...tegoryZ33742QQihZ013QQitemZ230055552134QQrdZ1

That is the only thing that I could find. I should be fine with buying an ebay intercooler, cheap piping and then piece it together from that?

 

[hubz91talontsi]

Ok i have a 95 awd tsi also and im only getting about 13 mpg, ive checked my spark plugs and all that.. I have a 3" megan racing exhaust..Trying to figure out why its so bad...any help?

 

[Talesin]

Generally when there's a major drop in fuel mileage, that tends to be the front narrowband O2 sensor going out. The rear O2 sensor on a 2G (1Gs only have a front sensor) is only there to test if your catalytic converter is working and throw a code if not. It has NO effect on your mileage.
Though yes, a manifold exhaust leak would do it, especially if the car was into the shop to have that new turbo put on (which I really don't understand, given how easy it is to replace a turbo on our cars).

The easiest way to test if your front narrowband O2 is still good is to grab/borrow a logger, and log ONLY the front O2 (for faster frame captures). It should be cycling up and down, between 0v and 0.70-0.95v steadily, even at idle. If it's not cycling, it's time to replace the O2 sensor.
And that's a great price for a replacement O2... the one I picked up ran $85. You should replace your front O2 sensor at every timing belt change.